The crashing out would be caused by something in the AIW file.
But I have seen rF AIW and GTL AIW, there is no difference.
Any difference should be in the hard-coded stuff, not the AIW.
That said some tracks are made for online (people, with a brain) races.
Track limits may be taken a bit wider in order to prevent cut/track warnings.
It does mean the AI can go pretty stupid lines there.
I have the track, and seen AI hit walls pretty often. They are stupid...
Basically what we are missing is a variable HOW MUCH the car may deviate from the ideal line.
But all we have is a racing line, and limits how far AI may go.
They could, in theory, act like drunks withing that limit.
There is also a 'talent' file - basically determining how much a certain driver 'messes up'.
It also determines if he is good at overtaking, braking, following and everything.
I played around with it in the R8 Gordini mod, and yes you can make them go nuts.
Like make them very agressive but prone to all kinds of fail. Or late-brakers.
Or the kind of behaviour you mentioned.