Technically you are in the wrong here. It is against FAA and IATA regulations to pack any device containing a battery in the cargo hold due to the risk of there being an unconfined fire. If anything you should have removed the laptop from the bag and brought it on board with you. If the FA/GA gave you any pushback for doing so remind them that they would be in violation of Federal law by accepting a bag with such a battery (and no removing the battery cell from a laptop doesn't remove the risk since most laptops have an embedded battery for CMOS).

-James