I have a co-worker at work who I have figured has given me the wrong advice or wrong impression more than once (like "oh its ok to come by this time" while I found out later it was not permitted by company policy).
What do you call such a person?
EDIT: Thanks to everyone for the answers. I was looking for someone doing this deliberately.In my opinion the word I would use would be a "deceiver" or a "misleader", as they convey the sense of deliberately giving a false impression or leading in the wrong direction.