I think it was just easier for everyone on her team to blame it on him instead of taking responsibility for it because of his recent actions/troubles. People are so quick and eager to believe everything about him that her team pretty much didn't care if they piled more rumors on.
People should start taking responsibility for their own actions, reminds me of when Joe Jonas said Miley, Demi (and I believe Selena) made him smoke weed and Miley got asked about it and said "no one can make you do anything that you didn't already want to do"
