Max dips his shirt and elbow into water during the baby class. Moments later, his shirt is dry.
It is quite improbable for Max, 99 and the Chief to beat KAOS's flight from Washington to L.A. "barreling along at 70 mph by train". The average flight time between the two cities is just over 5 hours non-stop. A non-stop train ride at 70mph would take approximately 32 hours.
Miss Valerie and her compatriots disguise themselves as a flight crew, but unless they just happen to actually know how to fly an airliner, there must have been a real pilot and crew who could have been reached by radio and ordered to make an emergency landing.
The Chief, Max, & 99 rush to Los Angeles to intercept the KAOS agents, with the Chief implying it is the only hope of stopping them. However, they could have been stopped by having the FAA order the plane to return to Washington, or having the Air Force intercept it and force it to land, or simply phoning the LAPD (or the Los Angeles FBI office) and having them board the plane and arrest the KAOS agents on arrival.