Rump... Butt.. same thing right?

This past weekend my mom called me about the recipe I posted for the pork boston butt. She was making this and wanted to make sure she was doing it right. So she told me she had a RUMP ROAST and I was thinking rump, butt.. same thing.. I wasn't thinking. She was making a roast out of beef NOT pork. So I told her to rub it down with brown sugar and cover it with apple cider etc.. Hours later I was at her house and went to look at the roast and realized it was beef not pork. Mom and I were dying laughing. It all worked out and we saved the meat from being cooked in apple cider. I just thought it was funny.