Lol, priceless. 1st. He left the fry in the bag for an hour (who knows what temp the room and hence the water was), and then did he acclimate them properly, sounds not. And he didn't quarantine them. All his mistakes. No blame on you at all!
Plus, how much bigger is a platy than a guppy FRY!?!
lol, this is hilarious!!!! my guppy fry are apparantly "saints" and not super villians! they live harmoniously with all the other fry! Maybe the drinking water was spiked!