Interesting, thanks !
So the ONLY way to know for sure is to disassemble ?
Its actually worse than this; you never really know if you are stomping on something.
In this particular case, you know your'e stamping on something having to do with the RSA check, so you can disassemble the RSA routine and determine it that way, and move it to another arbitrary location.
And even then it doesn't tell you the new location isn't being used elsewhere.
You could try logging potential locations and see if they change, but even that isn't 100% because when YOU decide to change that location, maybe some other code is monitoring that location for a change.