It makes me happy to see this. But still I'd advise using developer agreements, if you want the control of the project. And correct license of course!

And it's proof that like Oracle suing Google over 10 lines of code, it's enough for one or more contributors to claim ownership of some (small) part as a basis to take, say, Netgear to court. Thus you don't necessarily need to assign copyright over to a single person or organization.