Vilem Otte said:
The problem might be IP ownership for example. Let's suppose we both work on project which you own, but I do add my IP to it (3D models, sounds, but even code, technically whatever). But we don't have a contract - who owns whatever I create and add the project then? Because if it is the creator, and not “the project” (either company or person owning the project), it can create massive problems in future.
I mean sure, all sorts of stuff can happen. However, I've heard many people claim that something like less than 5% of revshare projects and maybe even lower, get anywhere near to the point that money is being divvied up. I can easily believe that, looking at INAT posts on reddit. Seems like getting people to work on a project and stick through until the end is 95% of the battle. If you get to the point where you are worried about IP, you are probably way ahead of the curve. So stuff that gets in the way of finishing the project can be considered bad.
If the OP doesn't want to “hire” this guy, that's fine. I'm not saying he should or shouldn't. But I can see the other side of the coin. At less than a 5% chance of getting anything significant for your work, it can feel insulting to have to sign something. I'd bet the guy is looking at this more like volunteer work.