The Doctor tried to resist, but really. When a large, exceedingly strong, wooden creation wanted to take something from you, it was rather difficult to stop it. Especially when another of them was concentrating on keeping a hold of him. He really wouldn't have put it past the Master to have them break his hand to make him let go of the sonic either, so in the interests of keeping his bits all in one piece for when he needed them later for his daring escape, he flicked the screwdriver off.

"It's off, see? No harm done, I'll just put it back in my pocket, shall I? Then we can go back to, you know, other things." He smiled hopefully and slowly moved to slide the tool into one of his pockets.