How long are the tongs you have? I guess my only suggestion would be to try slightly longer ones, and possibly you won't react as much if the movement is a little further away. But... I don't really know you, so I can't say for sure, lol.

One of my friends, like, would have the startle reflex to this very specific sound effect in a video game she was playing, and she knew it was going to happen when she hit the button, but it still happened. It was so weird to see, but I believe you. I wonder if you could google whether there are techniques that can help you overcome the startle reflex; perhaps there is something you can practice that is not feeding your bp, that will still help once you need to do it.