Ben's never seen on the Melonweed side of the gorge after jumping it, and Ripburger would plausibly have access to a helicopter. But how did Michael, Sid and Razor get across the Gorge, to be seen hanging out with the rest of the Vultures?
How did Mo get into the shareholders' meeting? Ben needed to use Mo's secret passage to get by the front gate, but she got in some other way, and even ended up with a front-row seat!
How did she get there faster then Ben? Ben left her back at the hideout with the hardtail parts, and no amount of time passed. At least, so long as Ben doesn't get stuck with the wall-kicking puzzle.