Faster drivers often think that the lapped car will simply vanish, it happens a lot in simracing too.. I've heard and even got complaints my self when the lapped driver refuse to bolt to the grass (really, someone once accused me of slowing him down and expected me to drive off the track since he was 2nd and fighting for position to 1st, i was in front of him only one turn and let him pass at the next short straight...).
With the speed i have, i've gotten a looot of practice of how to behave when being lapped and start of the straight is not the place to veer away from racingline or to slow down.. If there is a second lapper following very close by, that move can cause an accident when that second lapper can't see the lapped car. If the lapper goes off racingline in effort to make a pass, the lapped driver is required to drive using normal driving line with regular speed. Vettel just thought that Karthikeyan will put brakes on in the start of a long straight, not gonna happen..
It is the lappers responsibility to make the pass and the lapped driver is responsible for providing a safe opportunity for it... Karthikeyan hasn't got the talent or speed and should not be in F1 but his penalty is ridiculous... Old topic, will stop posting in this now..