Looks like it. Along with another donator account that hasn't posted since 2013, locked them both.
I remember seeing a member Donator signing up for secondstrade campaign after long period of inactivity, if you can check trash(if user deleted posts go there that is) you might wanna check that account as well.
I would think signing up for a signature campaign, especially secondstrade is more of an indication that the account was sold.
Also only deleted threads go to the trashcan (accessible to all mods) while deleted posts are only viewable to admins and need to be looked up by user and by thread (IIRC). So you would need to know the handle of the account to see the deleted post.