Other mistake: The first time Rachel brings the team coffee, she has six coffees on a tray. There's five cappuccinos and one regular coffee for Harry. On the tray there is five coffees on one side and one coffee at the other side, obviously being Harry's regular coffee, so that Rachel would be able to tell the them apart. But when she gives Harry a coffee, she gives him one of the five standing together, so he obviously got one of the cappuccinos.
Other mistake: During the end-credits, someone's title is listed as 'Mr. Bronson's Driver' instead of Brosnan.
Other mistake: When Harry gets out of the truck at the motel to retrieve E.L.F., there appears to be a blue & white storefront sign in the background that is lit, when the rest of the town is dark due to no power. Either that, or it is a really bright, white, non-electric sign that has been completely unaffected by the ash that is coating everything else in town. (01:26:40)
Other mistake: When the lahar slams into the bridge, it seems strange that none of Paul's windows shatter while he's trying to get across. A lot of mud and debris slams into all three vehicles, but their windshields and windows remain intact. Also, the bridge entrance is washed away, but the rest of the bridge remains standing, until it tilts upward and disappears, taking Paul and his van with it.
Suggested correction: Or the white coffee cup was for the guy that's obsessed with her coffee. Considering that it's a little bit bigger than the others and that I'm sure she wrote what each one was on the cups before handing them out, then it's very likely that the one she gave Harry was still a regular. The Grant Heskov-apologies if misspelled-also has the white cup with him, so it is possible that she gave everyone the right one.