>>12
The second train.
They depart from station A, and then realize at the same time they were supposed to stay at station A (what fools!), the second train has slightly less inertia so brakes and goes the other way quicker (also has a headstart).
All onlookers do concede that it was, in fact, very close and difficult to discern which was the faster train, but all came to agree it was the latter indeed.