Yeah, from what I learned it is not a must when it comes to neurological examination.
I remember once taking my female friend (who I knew was very ticklish as I tickled her several times beforehand) to my physiotherapist friend while staying in the office and chatting with him as he examined her. She was lying on the table, and when he was checking her sensitivity with the Wartenberg wheel on her arms and legs she already gave a few ticklish reactions, so being a cheeky bastard and pretending I was interested in the medical aspect of his practice, I was like "shouldn't you do Babinski as well?"
Not sure if he figured out what I was going for or not, but he did say something along the lines of "Babinski is usually not a standard part of reflex examination" before he turned the pinwheel in his hand and slowly stroked both of her feet with the handle which resulted in pretty good squeals and giggles.
As I never got to tickle her feet myself (only ribs, knees, and armpits) I considered that a personal victory by doing so through the other person. Ah... good times!
