What I can see is just about word vs word, there's no clear evidence about the proof chat which from Small Rabbit since it's already been deleted. And Small Rabbit is blaming the developer according his story, the developer tried to scam him. Of course it's will hard to prove which is wrong between them.
I can't say it's a scam, but it's more like not professionalism when handling the campaign since the reward pool is suddenly changed as he want. However the reward pool should be fixed first before starting the campaign, so it wouldn't hurt anyone.
Right, and what I don't get is why would some Project owners be asking you to send back some amount of funds that are already marked for Bounty payments? are they not suppose to have every other payment for their project sorted before engaging in any form of bounty campaign? I believe that this totally shows a lack of project planning and execution from both parties and the way Small Rabbit easily just returned the funds!!!