The London club emerged from the home leg with a valuable lead to take to Anfield.
While the Reds will still fancy their chances, Slot admitted that his team were undone by a moment of brilliance.
He stated: “It was a good goal, let that be clear. A ball in behind, a cut-back cross, (Lucas) Bergvall scoring, stayed really calm, finished it off, but I don't think you're interested in that. I think you're interested in the moment before. When I just walked in, I think I saw Ange sitting here on Sunday, something happened and I think Spurs weren't happy with a few decisions that were made on Sunday and many people always say that this will eventually match up in the end of the season.
“I’m not one of them that believes that because sometimes you can be unlucky in a season, or lucky in a season. On Sunday, a decision went against them, maybe today a decision went in favour of them, which is, of course, very unlucky for us because I never felt we were going to lose this game.
“Especially not after the first 15 to 20 minutes because I did feel Spurs started the game better than us. But after that, in my opinion, we had most of the game control, played most of the game in their half, had much more ball possession and then a moment like this, if you go down to 10 for a few seconds against a team that can play good football, like Tottenham can, it's far from ideal.
On whether Bergvall should have gotten a second yellow card for a foul prior to scoring the winner, he added; “I don't think there is any debate about that. They say he didn't stop the counter-attack. I think every manager would prefer if the tackle being made now 40 yards away from our goalkeeper – I don't think you really stop a counter-attack then – every manager would prefer to get a second yellow card for the other team than to finish that counter-attack with a player less to play that counter-attack with. If that is not a discussion then the next discussion is if it was reckless enough, (so) just give advantage, then just come back and say, 'Yeah, I thought the tackle was still too reckless.' So they still have to give a yellow.
“In the VAR decision, he had to tell everyone what his decision was and unfortunately he didn't have to do this with this decision. Things happen. Very unlucky for us. The good thing for us is that if you ever have to lose a game, it's better that you lose one when there is still a second leg to be played. (It's a) far from ideal starting position for us because they have a really good team, probably some players come back for the second leg. So, far from ideal to lose here but if I ever have to lose, I prefer to lose if there's still a leg to be played. Then it would've been only this game.”