Crit enviorment match 4 bypasses protect tile?

Unknown

Just had this happen twice in the sentry pvp.

I've got a Cap blue protect tile out soaking up 291 damage from enemy attacks.
The opponent is down to a level 23 loaner sentry. It makes a match 4 on environment tiles and hits me for 33. No way that should happen right? Or am I getting my math horribly wrong and an environment match-4 from a level 23 Sentry should be doing 324 damage?