 Which isn't something the guard did?
You will, you know, so why quibble about it? At least, you always have ... or do ... or will. Yes, it'll be pretty obvious it must be a time machine. That means you either carry a small time field with you, or you are catching a small increment of time from the main field. There's no feeling of acceleration—some kind of false gravity they use in the future. Some of them can be decoded to stationery shops, fountains, and the like. You wouldn't care if you saw a man in a leopard-skin suit; you'd figure it was some part in a play and let it go. "Thanks," you mutter, wondering what kind of civilization can produce guards as polite as that.
 help him carry the atomic generator to the time machine
 help him carry the atomic generator to the time machine  help him find the atomic generator  hand him the patent and other helpful information  give him time to take it out of the building