He/she said he's eaten twice since they've had him. I'm assuming that means they've had him at least 10 days then. I handled mine after five days. I even cheated and picked him up on day two to move some stuff around in his tank. Never had any issues with him going off feed or acting stressed. I think it depends on the snake. My guy was a little jumpy when I got him too, but he was young and hadn't been handled much. I did keep handling him short at first. Five minutes a few times a day. Then I went up to 10/15 twice a day after a week or so. Now I can have him out for an hour or so before I get tired of keeping him out of trouble and put him away.
Don't be worried about him being jumpy. Just lift his hide up, grab him, and support his body. Nothing to it.