that's where self esteem comes in. just like spousal abuse, you need to have the strength of mind to "know" you're not at fault.
The worst thing is you can hardly set up a phone line for "male victims of rape", if a victim wanted no one to know, then calling a phone line which deals exclusively with the matter is as good as telling everyone. But if you just seek general psychological assistance, or risk calling a normal rape crisis line, there a chance you may not be dealt with properly, or god forbid, not be taken seriously.
I don't know if this is already the case, but If I were administrating such things I would contact all the "rape crisis" and some general psychological services with a referral service, in other words set up a system where a male rape victim approaches a regular outlet and that outlets refers them onward to a central specialized service.