Last weekend I faced a weird situation during Top8 booster draft at a PPTQ.

Players where drafting third booster and at pick 13 I was called attention by one of the drafting players. He had received 3 cards instead of 2.
I stopped the draft and asked all the players to check if they had the correct amount of cards in their piles and in the booster they were receiving, but there were no missing cards anywhere.

Looks like that booster had 15 cards instead of 14 and the player that opened it didn't realize of the error although I asked all of them to count the cards for each booster they opened.

I know this is not a common issue, but I'd like to hear how would you handle and fix this situation.

This late in the draft there's nothing you can really do, so I think you just carry on and tell the players that that's why you need them to count the cards.

Hello, David!
I think that unless your investigation discovers that someone has drafted a card from his or her sleeve, or has picked a non-foil basic land, at the moment of realizing the mistake you are limited with options.

Figuring out who was the person to open that booster, whether or not he or she counted the cards after opening, along with recounting the cards by rarity (and separately accounting DFCs) is good starting point for investigation, in my opinion.

MTR 7.4. allows HJ to allow abnormal product, so if I believe that this was, in fact, abnormal product, I'll allow it.
I'll also go with a Warning for TE-DPV for the person that cracked the booster and didn't count the cards, if there was an announcement to do so.

Kind regards,
Lev