My dad accidentally took 1 hydrocodone pain right after taking 2 advil, (ibuprofen) is that okay?

Shouldn't be problem: but am not sure how you "accidentally" take a hydrocodone pill. Unless your father is very sick, or is on other central nervous system depressants, a single hydrocodone (which until Zohydro came out contains no more than 10 mg of hydrocodone) should not cause major problems. Medications should always be in their original bottles, and labels should ALWAYS be carefully read before taking ANY med.