Honestly, this is 100% foul on Tomiasu, and the only reason it was not given is that he stayed on his feet as long as possible. This is not the first time we’ve seen that, instead of rewarding this behaviour, the referees punish it by not giving fouls and then VAR doesn’t overrule them because they are not classified as obvious mistakes…
The problem is consistency from refs. In the first half there were a few fouls given against Arsenal that were far softer pushes. You cant say some are fouls and then some arent when the ones that arent are clearly worse. If that push isnt a fou; then there are a handful that were given against Arsenal as fouls that shouldnt be.