That's unfortunate. But a good reminder that under optimal circumstances people should go to pick up the puppy in person, scope out the kennel, and meet the parents & breeders. I'm frankly surprised that the breeders were OK with sending a puppy unaccompanied on a non-direct flight, or that it couldn't be arranged to meet the puppy at an alternative airport if no such flight existed, really. Though, I'm assuming you already know this, if I also assume correctly you've imported dogs before since you mentioned your affinity for training European bred dogs.
Hopefully it won't be too bad. Poor pup.. at least, though, your friend will have a few days of quiet.. pup's probably going to be understandably tired for a few days.
Just a few more hours!