Actually, it has been a while, but there is an interaction between THC and adrenaline. That is why running the next morning, and the accompanying runner's high, knock out THC hangovers. Get pulled over for reckless driving, weaving in and out? The adrenaline from fear will help sober you up. Not enough to beat a wrap, but it will help a bit.
If a person is too high and then is unexpectedly frightened? That is a good thing.
BTW, sexual stuff helps as well...there is a relation between THC, orgasms, fear, and adrenaline. But that is a story for another day.
Nice writing btw.