Campaigns/Missions & Other SPOILER Questions.

[flapane]

WARNING, SPOILER INSIDE

Hi there,
at a certain point I get a call from *a mate* (I don't remember his name) asking me to rescue his girl waiting in a Motel near Oxnard.
After I pick up her, I get chased by two guys with a gun and if I try to escape, my truck explodes (with a couple of gun bullets only, let alone their weird sound effect? LOL) and the game ends.
What should I do? Of course I WON'T restart the whole story from scratch just because it's not clear what should one do, in this case I'll sell it ASAP.

Thanks in advance.

p.s
I don't know if this is the RIGHT thread, so sorry for double-posting.