I think the controversy surrounding this play is that, as others have mentioned, we have seen similar types of challenges not sanctioned as sendoffs. What I don't know is whether there was any communication with PGMOL and the Premier League about a potentially lower bar for sendoffs. It's possible (but perhaps unlikely) that with Webb coming in, maybe he has started to make some of his feelings known and has started to influence some things. I can say that the bar for sendoffs in MLS/PRO is definitely lower than what we've seen in England. Taylor may have also been thinking with his "UEFA brain" having come off of his UEFA duty. In any case, a sendoff definitely was not a clear error in any case.
If this type of play happens in Italy, Spain, or France, I think it's a sendoff all day long and no one gives it a second thought (particularly in France - they are not messing around when it comes to dealing with misconduct this season!). But England has had a very high threshold for red cards for a long time and particularly this season.