As I scroll through a thread on my iPhone, I tend to use my right thumb. Three times now I have inadvertently put a bit of pressure down and managed to hit the "Report" button. Luckily there seems to be a gremlin and it goes off to an error page, but if/when that's fixed then you may be getting a few more "Report posts" than you expected.
But I don't know what the solution is - if you swap it over with the "Add Message" bit, then lefthanded MNers are going to be reporting posts willy nilly instead. Or maybe it's just me and I need to be a bit less cack-handed.
Other than that, the App is bloody marvellous - many thanks!