With my son having a disability, he wasn't potty trained til 5 years old. We still have the occasional accident at 9 years old, but that's because he will sit there and won't move FOR THE WORLD if he's intent on doing something, lol. He will rock side to side, dance, and then he'll get up, run towards the bathroom... not use it, run back. He's afraid of missing something. When he is finally going to burst, he goes. #2 is different. He does the same thing as above, but sits on the toilet for half an hour to an hour.
... Then he comments on it. -.- Lol.
He went to a special school, and him seeing OTHER kids potty training really helped us. This school actually taught him how to go standing up.
Our only issue is he has no shame about his body (which is good) but bad in the sense that he has no problem pulling his pants down at the urinal because he won't just unzip and go. LOL.