I also never leave the aircraft until the truck shows up. Or at least watch carefully frommthe fbo window. Had a full load of pax one day, and the fueler didnt know what "tabs" meant, and so he topped it off. (40gal difference) I was 250lbs overweight, had to have then drain/suck out 40 gallons. Refused to pay the fuel removal, told them to contact my employer if you really think this is my fault. Never heard back.