artemis fowl - Why didn't Briar Cudgeon disappear from the Time Stop?

In Book 1, Artemis et al escaped from the time stop by drugging themselves to sleep.

In the same time stop, Julius Root "accidentally" plugged Briar Cudgeon with a tranquilizer dart. Cudgeon fell asleep, but did not disappear from the time stop. Why not?

Answer

Fowl Mastermind here.

The answer is simple biology. Artemis, Juliet and Butler are all humans [known as 'mud men' to the People]. Whereas the good Lieutenant Cudgeon was an elf. We can simply theorize that none of the People can escape a time stop, and that time stops only affect sleeping mud men-- especially since the magic was used in the past to deter mud men from intervening on fairy business [they hint about the elf and cobbler tale].

Another answer could be the fact that none of the People can leave a time stop until it ends due to their magic. Remember, though the generators for the time stop are technological, they are still using fairy magic.

TLDR; he didn't poof cuz he's a magic jerkwad.