Grammatical error in quest conversation

Pet peeve of mine, but I don't think this is a purposeful grammatical error (as some NPCs with accents / ways of speaking have).

In Western La Noscea for the quest "Scythe Extra Large" when turning in the quest he says: "I'm sure Aerghaemr wouldn't of wanted anyone dying near his resting place."

Needless to say, it's "wouldn't have" not "wouldn't of".

Some people actually say "would've" like "would of" in real life. It is technically wrong, but it's common enough that I believe it is written like this deliberately.