Pretty sure getting caught urinating outside in the State of Oklahoma can get you a quick trip onto the sex offender registry.
haha no it wouldnt, like LightningCrash said there has to be intent. Just plain out peeing behind an abandoned building and getting caught is disorderly conduct. You are probably thinking of indecent exposure which i believe under Megan's law does get you put in the registry but there has to be intent of lewd behavior to get that charge.
And Lurkerinthewoods' friend was drunk so that adds more to the case but the typical peeing in the bush on a road trip wont get you in that much trouble. And lurkers friend is a bit more obvious and blatant than what usually happens.