Liverpool had fought back from two goals down — Matheus Cunha's deflected opener and a Benjamin Sesko close-range finish — to level through Dominik Szoboszlai and Cody Gakpo. But Kobbie Mainoo's composure in the 77th minute settled the contest for Manchester United and left Slot having to address a result that his side should, in his assessment, have avoided.
He was blunt about the first half, when Liverpool were twice undone by set-piece and counter-attack.
"It wasn't necessary to be 2-0 down and it wasn't necessary to lose this game today. Although United deserved to be 2-0 up — let that be completely clear. We conceded two goals and they had a lot of strengths, but two of them are from set-pieces and the counter-attack and we fell into that trap with both goals. The first from a set-piece and the second we played through the middle where their players are sharp in the duels and a quick counter-attack led to the 2-0."
He outlined the adjustments he made at the interval.
"I said if we can combine coming into good positions with a bit more intent in arriving in the box — that's why I changed and put Cody in a number nine position — then we are able to do more than only having ball possession. And that's what happened in the second half."
Slot was asked directly about Sesko's second goal, which VAR had reviewed at length for a potential handball before allowing to stand.
"Yeah, if it was a touch, which I think it is — because if you know a bit about ball sport, you know that if a ball has a certain curve and the curve changes, there must have been contact. Then we should have a debate in football: is that then enough to disallow a goal? But I think the rule is if there was a touch it should have been disallowed. But I don't think it's a surprise to anyone this season that if there is a VAR intervention — if there is something that you could look at or could be left, could be right — then that decision goes against us. That has been the whole season. Every single time the same."
He cited the home Paris Saint-Germain game in the Champions League as a previous example.
"If I remember PSG at home, getting a penalty for a soft touch on Mac Allister but of course the VAR interferes and says no, this is not a penalty."
Despite the defeat, Liverpool remain fourth, needing three points from their final three games to confirm Champions League qualification of their own. Slot acknowledged that reality without allowing it to reduce his irritation at the result.
"I wouldn't say concerned is the right word, but I'm completely aware of the fact that we need three points. That's why I was so annoyed that we didn't pick them up today. Although we didn't deserve to get these points in the first half, if you are 2-2 coming back from 2-0 down then you should at least go away with a result."
Liverpool arrived at Old Trafford without Mohamed Salah, Hugo Ekitike and Alexander Isak through injury, leaving Gakpo as the focal point of a depleted attack.