Riccardo looked to be just unlucky to hit uneven ground with his wing but he hit it pretty big time, nothing out of ordinary in wing going its own way there.The Vettel one looked a bit odd at first as he didn't seem to lock up the tires in a dramatic fashion, but the replay clearly shows the car was vibrating very hard just before the wing fell off.
So as It's been said I don't see reasons to be worried based on that. Actually, perhaps the most unusual one was Kubica loosing his wing during the start in Australia in what seemed like an end-plate damaging contact, but it's impossible to know without knowing exact loads, angles and forces which were in action when the contact occurred.