So they arent checking for alcohol, and you are asking us if they can find it, or if they will care enough to report it.
First of all it's not like they can see the alcohol in his urine if it's still their when he pees, they have to test for EACH thing they are looking for, and if they said they arent testing for alcohol, then they won't, because it costs more, and if this test is for a job they definitely won't do anything more than what they are supposed to.
Second of all it takes about 1 hour for 1 standard drink of alcohol to leave your system, so if he drinks thursday night and doesn't finish until friday at 8 am most of the alcohol would have been processed by saturday at the latest, and all of it should be out of his sytem before the sun rises sunday morning... stop freaking out, stop babysitting your friend, he definitely doesn't want it if he is ignoring your advice, loosen up and enjoy life without thinking about the numbers and such, because before you know it all of the numbers are gone and your wondering where all of the years went...