They haven't been around but about 15 years. The Huglu made stock panels are robustly wedged into the reciever. I have never seen one cracked and maybe never will if the stock bolt is kept snug.
I had one that cracked at the head; it actually split a piece off. I didn't take a picture, so I'll try to describe:
Looking at the gun from the top, barrel pointed away from you - the top, right corner of the head came off. The split was maybe halfway between the edge of the stock and the tang cutout. It split back, about two inches or so. The split went down at an angle, and back to the edge. Sort of a wedge-shaped piece.
The Huglu was a De Haan U5E, which Mark De Haan repaired under warranty. He offered to replace it, but for my own reasons, I chose repair. I've no idea why it split, there were no apparent problems.
I also had a Ruger Red Label 28 ga split in the head, though it stayed in one piece. Ruger replaced the stock at no charge. In this case, I think it may have been a slightly loose through-bolt that was responsible. The crack started at the right/rear of the upper tang and travels towards the trigger.
Here's a pic of the cracked RRL stock:
