Some people will point casually with forefinger out, but the rest of the hand only slightly clenched, although I tend to see it in older people most often.
It seems the defense witness is trying to point out that the lawyer is confused about which hand was used, though the lawyer might also have been trying to solidify, by planting the suggestion in the judge’s/jury’s mind, that indeed, the right hand was used.
This is what I hate most about not being able to respond to prosecution when not directed to.
