Spurs were leading PSV Eindhoven 2-1 in Holland with 11 minutes to go when Lloris charged out of his area and upended Hirving Lozano to earn a straight red card.
The 10 men promptly conceded an equaliser to leave both sides on just one point after three matches in Group B and facing the prospect of little more than a scuffle for third place and the Europa League.
PSV’s opening goal also came from a mistake, by Toby Alderweireld, but Spurs boss Pochettino laid the blame at his side’s failure to take their chances rather than the brain fades at the back.
“I think it’s easy to judge the game,” he said. “If you didn’t win following what happened then you don’t deserve to be in the Champions League.
“This type of game, when you dominate and are much better and have the possibility to win the game, at the end that can happen.
“An action that was our keeper Hugo sent off, and afterwards with 10 men you concede chances. With the chances they scored and then it’s 2-2. Clearly that’s the analysis.
“I’m not going to blame any player. If someone is to blame it’s myself, I am responsible for the team. Not the player.
“Players are there to play. The problem is when you are so good, you dominate the game and create the chances and you can’t kill the game.
“Then an accident from Hugo and the decision didn’t help us, and you draw and it puts our qualification for the next stage in a difficult position.
“Was it a red card? In my opinion I think no, but we cannot blame the referee.
“Now we need to win three games that we have to play and some results that help us to achieve a place for qualification – but it’s difficult.”
Spurs may have made their best start to a Premier League season but their European campaign has been beset by self-inflicted wounds, from the late collapse at Inter Milan to Lloris’ gaffe against Barcelona.
And when PSV’s opening goal arrived, shortly after Harry Kane had clipped the crossbar, it was also of Tottenham’s making, with last man Alderweireld caught in possession by Lozano who ran through to score.
Lucas Moura equalised before half-time and when Kane nodded in a cross from fit-again Christian Eriksen Spurs looked destined for victory.
But Lloris injected further drama into the tie when he raced outside the area and cleaned out Lozano to earn a straight red card.
It proved costly in the extreme as back-up keeper Michel Vorm held out for all of seven minutes before the ball reached former Newcastle loanee Luuk De Jong in the area and he prodded the equaliser.
“This result leaves us in the same position in the ranking,” said PSV coach Mark van Bommel.
“Of course we wanted to win. It was a heavy night for us. We were leading, but then it is 1-1 and 2-1 and we had some difficulties against a really strong opponent. In the end we have to be happy with a point.”
With Messi watching on and cradling his broken arm from the stands, Barca had little trouble breaking down the Serie A-side, though it did take a quite unbelievable assist from Luis Suarez for Rafinha to open the scoring.
Jordi Alba wrapped up the game 10 minutes from time, but they were never in any danger of conceding an equaliser, as Mauro Icardi and Co offered next to nothing in attack.
Check out our Barcelona ratings below:
Marc-Andre Ter Stegen – Did well to react to a Politano cross that deceptively turned into a shot. Great on the ball. 7
Sergi Roberto – Preferred to Nelson Semedo at right-back and handled everything thrown at him – which wasn’t much. 7
Gerard Pique – His form is under the microscope and he just wasn’t tested enough to take away any conclusions. 6
Clement Lenglet – Two golden chances, two poor misses. Defensively he was sound, apart from one Icardi scare. 6
Jordi Alba – Some clever combinations with Coutinho and wrapped up the win with a wonderful touch and finish. 8
Ivan Rakitic – Pretty passing followed up by the end product that led to Alba applying the gloss. 8
Sergio Busquets – Inter’s ‘attack’ was anything but attacking and the understated Busquets played the key role. 8
Arthur – The diminutive midfielder’s stature only grows with every passing game. A smooth operator – born to play for Barca? 7
Rafinha – He was no mini-Messi, but Rafinha busied himself right across the attacking line and a smart run led to his goal. 7
Luis Suarez – He almost deserves full marks for the Rafinha assist alone. Full of menace and only improved as game wore on. 9
Philippe Coutinho – Walloped against the woodwork and took relish in shouldering some of Messi’s duties. 8
Nelson Semedo – Brought on to lock down the right flank, though the Nerazzurri barely intruded. 6
Arturo Vidal – Brought on in the last 10 minutes for Arthur, who has emphatically blocked his route to the first team. N/A
Munir El Haddadi – A few minutes to run around when the job was all but over. N/A
Rafinha returned to haunt Inter Milan as Barcelona eased past the Italians in the Champions League to tighten their grip on Group B.
Ernesto Valverde’s side remain top of the group with a 100 per cent record after Jordi Alba wrapped up a 2-0 win late on.
Rafinha netted his first Barcelona goal since February 2017 after he spent the second half of last season on loan at Inter.
Inter, the 2010 winners, struggled all game and are three points behind in second with Tottenham – who drew 2-2 with PSV – a further five back.
Without Lionel Messi, sidelined with a broken arm, Barca lacked their usual ingenuity and Inter conjured the first opening.
Ivan Perisic fired a dangerous low ball in and Mauro Icardi steered it over with Marc-Andre ter Stegen putting him under pressure.
But, slowly, the hosts built momentum and two tame Rafinha efforts were comfortably saved by Samir Handanovic and Clement Lenglet – who had already had a header well stopped – nodded a corner over after half an hour.
But two minutes later Rafinha broke the deadlock when he latched onto Luis Suarez’s classy cross to volley in from six yards.
The midfielder did not celebrate but it was a deserved lead and Barca almost grabbed a second just before the break when Milan Skriniar brought down Philippe Coutinho on the edge of the box.
The Brazil international’s free-kick hit Miranda to drop inches wide of the wrong-footed Handanovic’s post.
But Inter almost levelled five minutes after the restart when Ter Stegen was forced to make a vital save from Matteo Politano’s dangerous cross.
Handanovic then had to stop Suarez making it 2-0 as Barca rediscovered their stride after the former Liverpool striker cut into the area.
Lenglet was denied again before the hosts came inches from doubling their lead with 19 minutes remaining.
First, Suarez’s header was parried and, when Ivan Rakitic miscontrolled, Coutinho could only hammer the loose ball against the bar from seven yards.
But Alba did seal the points with eight minutes remaining when he raced onto Rakitic’s excellent through ball and drilled into the corner before Suarez shot straight at Handanovic a minute from time.