Superjambon

Hi, I just had an encounter with a really really reluctatn Aipom and wanted to know if that was normal. I managed to catch it after sending 52 Pokeballs, 2 Greats and 2 Ultras, even though it was lvl 6 and asleep -> then paralyzed. I calculated that it had about 10^-5 chances that this situation occurs, which seems quite abnormal. Is there an explanation for this ? Cheers,