It's not lefthandedness! It's just what your used to/conditioned to. I am left handed and I do it as she does in the video.
My left hand has the bulk of the fabric and as I come up on the pins its just a flick of the right hand to pull the pin out, easy peasy.
I didn't watch the whole video so she may have mentioned this but its also how I pin to ensure my points don't get cut off. I pin through both fabrics at the spot i want my needle to land, manipulating both fabrics as needed, then when my pin is through both I tip it to the right and push the point part towards the bulk of the fabric and secure. As long as I land where the pin first goes in the fabric my points stay pointy.