My best friend has a 2 1/2 yr old son and when they were in line in walmart she turned her back for a sec and her son got up and fell out of the cart on the floor (laminate or whatever it is). She FREAKED out! Then she found out the cashier SAW him getting up and about to fall and didn't say a dern thing. Anyways, he ended up being totally fine but it was so scary. The pediatrician just said to keep an eye on him, make sure he doesn't get suddenly sleepy, pupils respond normal, acts the same as he usually does, and the area doesn't appear to have blood under the skin (like internal bleeding or something under the skin).
My daughter fell out of the bed when she was a few months old because she learned how to roll and roll and roll, seeing as how I put her in the middle of a king bed with pillows around her. She hit a carpeted floor and I rushed her to the ER freaking out. They said she was fine. It's just scary when kids get hurt like that.
I agree with ML B. Get a grip mat for the tub, remember to wash it... if ya don't sometimes they build up soap or whatever and get slippery.