I know an illegal order when I hear one, and I would have told the NCO absolutely no way am I ‘deleting this’.
But thats just me.
Besides, what the worst that can happen? An Article 15?
Surely there was a follow-up question. Tell me that the witness was asked “Did Sgt X say why you were to erase the video? And if so, what did he say?” Either this question was asked and not reported, in which case the reporter is a blockhead, or it wasn’t, in which case the lawyer is.
It seems to me that tampering with or destroying evidence of a crime is usually considered a crime in itself.
An order to commit a crime would seem to be an unlawful order.
IANAL
Most junior military members do not question orders unless they are clearly illegal.
They are taught to follow orders.