Saw a guy do both one day at the Big M ramp. The walkway to the dock was under water, water there was about knee deep. The poor guy launched his boat, tied it up to the dock, then as he reached the part of the walkway that was under water, he slipped and fell sideways into a foot of water. He got up, wet and madder than heck, decided he was going to go home (it was a chilly fall morning), backed his trailer into the water, put the boat on the trailer, tried to exit the boat by going over the front side, but somehow tripped and fell sideways into about 6" of water on the concrete ramp.
That one hurt.
For the record, I did offer to help (twice), but he insisted on doing it himself. But, it could happen to any of us, really pays to be careful when loading/unloading the boat.
And also for the record, I did a face plant myself once back when I had my 17' G3. Parked it on the gravel next to the ramp, tried to exit over the bow, one foot caught hung up on the railing, down I went, just barely had time to get my hands under my chest, but still went down hard. One of those things where I did an inventory for about 30 seconds before I decided to get up. Fortunately nothing was broken.