Eh, I find little remarks like these barely worth commenting upon. The fact of the matter is both candidates and their VP picks have been literally on a bus or plane non-stop for months now, with minimal sleep a night and having to meet and speak to another thousand or so people a day. You will flub your lines or ramble incoherently at some point, guaranteed. I personally will allow for them to be human.
I agree with this view, they are tired and been doing this like a job, it's hard not to make a mistake. so just let it be, a human mistake.