Yes when there is a legit defect. People getting injured on onewheels are pushing the board to the max, ignoring the warnings and face planting when the board tops out.
I've read hundreds of crash reports, and never seen more than a handful that weren't a direct result of the user's actions. Actual system failures are vanishingly rare, and most nosedives are only as bad as they are because the rider is traveling at an unsafe speed and has not invested in the training or equipment to fall safely.