If I am not mistaken, on the way to Helgen you pass up the Falkreath Stormcloak camp. Why do the stormcloaks not interfere with the imperial wagon that is taking Ulfric as prisoner. Even if the stormcloaks at the camp did not know Ulfric was going to be passing in a wagon, the camp is not that far from the street and the stormcloaks could have easily overpowered the imperials in sheer number. Do you think the camp location was something overlooked when Bethesda made the game?

It's not there every time.
Some of my games have open space where that camp is.

You don't pass the camp during the opening sequence. At the gate you Fast Travel to, there's two roads. One that goes straight and one that sort of curves off. You're on the one that sort of curves off.