Is moololi from tunisia on drugs?

Question

he broke is pb by 17s when he beat hackett in the 1500m swim

Answer 1

no. the 1500 is so long that taking off alot of seconds is normal.

Answer 2

He failed to break Hackett's world record despite his American coaching.  

Improving 17 seconds may seem like a lot but, his race did last almost 15 minutes.  If you look at most racers in most events, when properly rested they improve about 3%.  For the Tunisian swimmer that means he should have improved about 20 seconds over his best time from this year.  So, he was right on target and didn't need drugs.