Okay ... now that I re-read it, I think I can re-phrase it ...
So, if I read it right, he is asking if he is from a two plate state (like CA) and visits a state where only ONE plate is required, he is asking if he can be cited for failing to comply with the home state's laws? I suspect, no. Not unless the visiting state has a code section that covers it.
For instance, if someone from TX drives here without displaying an inspection sticker - a violation of that state's laws - I cannot cite them for such a failure to comply with TX law here. Now,if as a result of this the TX plate was expired or unregistered, then he could be cited for operating an unregistered vehicle.