Kane is only offside if the VAR assistant (or referee if referred to the monitor) subjectively believes he is interfering with play. A case can be made either way. If I try and take the emotion out of it (easier to do given events 5 minutes later), I’d say that Kane’s positioning was largely irrelevant to the outcome as, unsighted or not, there was virtually no prospect of Neto saving the shot. It was hit very well and the deflection off Stephens took it perfectly into the corner.
I would imagine that would indeed be the justification for the decision.
Once the ball leaves Dan's boot, Neto is already starting to dive to his right, so clearly has committed to trying to save it on that side. He's committed, there's no turning back, he's in mid-air. In the replays you can see that he is getting nowhere near to that ball, because of the deflection, Kane or no Kane. The fact that he dived to the right at the right moment suggests that he saw the shot clearly enough and was able to react to it. He was just unfortunate that the slight deflection took it beyond his reach.
I CAN see how VAR could rule that Kane wasn't interfering in that passage of play, i.e. the shot which Neto clearly saw (no), the deflection (no) and the failure for Neto to reach the ball (no).
Not saying that I agree with it, but being fair I can see how VAR, if purely answering the question "Did Kane interfere ?" could conceivably conclude "No".
It's all about interpretation unfortunately. You could probably make a case either way. The fact that Neto didn't make a fuss about it suggests that he accepted that it was just an unlucky deflection.
Oh and it was Spurs, who were losing at home at the time.
Oh and it was Kane being checked.