RE: http://shock.military.com/Shock/images.do?displayContent=121416
There is no regulation prohibiting a member carring something in the left hand while rendering or returning a salute.And beyond that, the Commander in Chief should have the respect he deserves no matter HOW he returns the salute. All the more important to have a CiC who publically respects the Military and does not look on it with disdain.

I don't think the two fellas at the bottom of the ramp give a hoot how he saluted. He could have square-gaited down the ramp, put the dog on his head and flapped his arms like a duck for all they probably could see. Eyes front, everything per timing.
Tax payers money well spent on routine ceremonial drill events.