It does sound pretty chaotic, which I guess is lots of people trying to make a decision quickly, but there are various references to the law mentioned in the Ake video. They mention "line of sight" almost immediately, then "offside position" and finally, "has he made an obvious action to impact on the ability of the goalkeeper" which is a paraphrasing of the law.
They then focus on whether it's having a clear impact, and they seem to agree fairly easily that it's not clear enough to say yes. They talk about Leno having sight of the ball the whole time, and the time to make a full length dive.
Given the decision they came up with at the end, I'd be pretty happy with that review. Webb makes it clear that he'd disallow it, but his own language about the impact on Leno is pretty wishy-washy. The VAR argued that it was a subjective decision, and Webb, even with time to think about this, still uses weak language, using words like "seems" to have an effect on Leno, or "we think". All very passive, rather that "it has an effect", and "it is".