Originally Posted by
regional
The PM told me he was going to deactivate certain deice items, while leaving others still on. I was doing something else and he had the aircraft at the time. I looked up and acknowledged what he did.
So you were running abnormal checklist and the PM was actually PF at the time. Why would he be doing anything other than flying? You said you were doing something else. Shouldn't it have been the checklist since in fact you were now PM?
It seems there may be more to the story.