Sounds like Maher is what we used to call an Indian giver in my childhood. I’m unsure what inoffensive term has replaced it.
Out of curiosity, I just checked it at Dictionary.com, but they don’t offer any alternative:
http://dictionary.reference.com/browse/Indian+giver?s=t
I think welching is an alternative.
There was even a hit song in the late ‘60s called “Indian Giver.” Can’t recall who recorded it though.