I'm going to speak up for the photographer/lawyers here.
I don't practice any more, but when I did, there were times when I would encounter issues where I felt that a question was out there that was just begging for an answer.
And as I encountered the Vivian Maier story, including the John Maloof movie, I kept getting the same feeling - what about the copyright issues?
Mr. Deal may very well end up making some money out of his legal work on this - so what? Someone needs to do that work if the issue of copyright isn't decided authoritatively by a court with competent jurisdiction.
If Vivian Maier had lived and died in my jurisdiction, the rights would have been held up until they were satisfactorily determined, and most likely that determination would have been made by the BC Supreme Court, as part of its jurisdiction as a probate court.