He says that it wasn't in a repo, so it's a bit weird that it would delete all his files, it looks more like he had an initialised repo and hadn't committed the files yet.

I don't even know how you could work 3 months without committing, even working on a throwaway thing for more than a few hours I make a new local repo, it doesn't cost much.

Also the files are not gone, they are still on the hard-drive/SSD it's not that hard to look up file recovery software.