that was good of him. it would have been picked up on your site. not expensive so don't worry you have not cost him a fortune. i think it would be best to give the eggs a miss. i had to treat mine last year plus treating some for infectious broncitus one had a no eating for two weeks i can't remember which. the good new is that you should not have to treat the birds again. they will gradually get used to the bug. if you only treated for one day with the wormer you need to do a full worming as soon as you get it, if they are only just coming into lay then you won't miss to many eggs. try putting a little cider vinigar in there water it helps make the gut more resistant to parasites.
just checked don't eat whilst treating. give it a day then they are fine.