Though that's where you want to check, the spoilage bacteria on the butt's surface were actually keeping the butt safer. Spoilage bacteria are competitive and, during the time in question, would pretty much disallow pathogen growth at the likely ambient temp. Cooking will destroy the spoilage bacteria and will pasteurize the meat.
But this alludes to the problem I noted above with already cooked/prepared foods. With cooked/prepared foods the spoilage bacteria were already killed off. Though they will colonize eventually (which is why food spoils after cooking as well), their low numbers after cooking opens the door to colonization by pathogens, especially Staph. Keeping foods sufficiently hot after cooking, or cooling relatively quickly then fridging or otherwise keeping chilled, thwarts Staph outgrowth. It is when hot foods are not kept hot, or hot foods are chilled too slowly after cooking, or cooked, chilled foods are allowed to warm, and there is enough time involved (this is operative), that problems can arise. Without the spoilage bacteria to keep them at bay, Staph can outgrow exponentially. Over time they will reach a critical mass and once that is achieved they produce a toxin. It's the toxin that makes people sick. It is also heat stable, i.e., reheating the food will not affect it at all.
(Not trying to freak you out here. I don't see cause for concern. Just illustrating why cooked foods can potentially be more dangerous, and how that occurs.)
