~snip~
But there are risks:
* some wallets are only partly open source
* some (fake) wallets just put something, anything to git (I've seen directly a zip with the exe once in the past) to trick newbies
* you can find on git a lot of clones, some maybe even malicious of the actual wallet
* the presence of source code doesn't mean 100% that the binaries were actually built from that source
All in all, no matter how much you hate that people didn't telly until now what to look for, you will most probably have to rely on others' expertise whether a wallet is indeed open source (and legit).
There's also always the risk that the actual code does something you don't want, even if it's posted completely open, and the binary created exactly from that source code (or even you built it yourself).
You (or someone else in the community) should read the source code and check to see what it actually does to make sure it's safe.