The only way to drive with no problems in demo, is:
1) Drive fast enough to be far from bad racers.
2) Avoid the bad racers.
At T1, from 6th to behind, will be a complete mayhem... You need to find a good line to avoid who spins at exit and avoid who goes wide.
If you are in front of a big pack of faster drivers, they gonna hit you, maybe not on purpose, but because they want to go faster and need to pass you.
Its racing things, you need to be fast enough to be far from crashers, and for dont disturb the race...
Also, people gets irritated too, and drive aggressively. This is hard racing, people wont get you all the space, sometimes being unfair...
All that i can say, is: Happens. Even at top categories like F1, Indy and GT...