[Wrong files syncing into folder]

OK now my client says he can't uninstall BTSync and it F'd up his computer (a mac). I don't know aything about macs. Is there a trick to uninstalling it? He says every time he tries he gets a message that it's running.

[Wrong files syncing into folder]

That title may be a little confusing but will make sense.

I have used BTSync on my own network and it's been awesome so I wanted to try sending a large file to a client with it, who is on a mac BTW. So he installed it and I was on the phone with him as he entered the Secret I sent, then he made a new folder and selected it. According to him the folder started filling with hundreds of files from his own network. Nothing having anything to do with projects I worked on.

Has anyone seen this happen? Could it be a mac only bug?