There is not, however ANY evidence that the care the OP's mother was negligent. It is possible for there to be injury, including facial trauma, without there having been any negligence. Since the hospital is barred by Federal law by showing the chart to the OP, the OP does not know what has been documented - he knows only that one doctor stated that the fall had not been documented. Which could mean that it isn't, or could mean that the doctor was mistaken, or could mean that it's been documented since the doctor last looked.
I don't know that there wasn't any negligence but I don't know that there was. I don't know what was or was not documented but there's no proof either way. It's impossible to say for certain, in either direction.
And neither does anyone else here, no matter what their past experience has been or what they "feel".
Two things I am tired of typing: 1.) A wrongful termination does not mean that you were fired for something you didn't do; it means that you were fired for a reason prohibited by law. 2.) The above answer, whatever it is, assumes that no legally binding contract or CBA expressly says otherwise. If it does, the terms of the contract apply.