Another app
It finds stuff like this
And tells you the line!
It's got the same interface as my Return bug checker, so read there if you want to know how to use.
Due to it's nature, it may not find everything. I have it checking each line for keywords like "return" etc then if it finds none, gives you a message.
It is also a beta, so it may get false positives. Please copy/paste both lines here if it happens to you so I can see what caused it.
Pm me if you want code.
Thanks to Haxorico for the suggestion.