If you go look at the actual boxscores, Paulino didn't come in to pitch. Troy Percival did.
Did the owner in question have an illegal player (Percival) on his roster, and did admin have to switch him out for someone? I have seen this before, when that happens the new (correct) player absorbs all of the original player's stats. That's my only explanation. But again, look at the actual boxscores and read the play by play...Percival was the pitcher.
There is no way to engineer a position player to come into the game as a pitcher.