Anyone can and does make them. If you don’t, you aren’t human. Even the conservative icon Ronald Reagan stumbled, and was vilified for them.
This is asinine. If people don’t think she is qualified, fine. Say so. But to indicate this is a disqualifying even is dumb, and anyone who uses this as a cudgel to make that point is a dimmer bulb than Tina Fey.
I don't know what advice a coach would give Sarah about her pitch, but Sarah would be well-served to slow down her speech a little and pause for thought before making complicated or potentially sensitive comments.