The rule makes no sense at all. How can you exit the course, re-enter at the same point AND gain an advantage? The second sentence is redundant.
The first sentence is the rule, but it appears that what they meant was actually you can rejoin the track anywhere you like, so long as you don't gain an advantage. That needs to be qualified with the reference point for the judgement of advantage, is it an advantage compared with not crashing, or compared with not having to rejoin where you left.
It would still be a very subjective rule, so perhaps the best approach is to just delete the second sentence and enforce it as is?