If Phelan and Todd have any sense (and they are the two characters I do expect sense from on the Cobbles) they'll let Vinny take all the blame for the scam. Tell the police that he was in charge of the business and finance side of things, Phelan was in charge of the actual construction side of it and Todd was just their employee. Vinny pulled the wool over their eyes too - they had no idea that he was planning to do a runner.
If they want to try to generate a bit of sympathy from the locals, they can even blame themselves for Vinny running; they say they were starting to ask questions about why Vinny kept delaying the ground breaking and saying all the flats weren't sold when Todd was pretty certain he'd signed up enough people. They must have scared him off, so sorry, never meant too.
I can see them getting away with this, but I don't think Phelan's going to be able to stick around; if nothing else, his pride won't let him stay where he's had to crawl to people.