Excuse my ignorance, but with regards to the second offence...
I would guess that the legislation doesn't stipulate which "drugs" does it?
That gives a prosecutor tremendous latitude doesn't it?
I mean if one was sneezing excessively when they passed through security inspite of their anti-histamine intake (didn't hayfever sufferers used to be excluded from holding an ATPL?), if a vindictive security person was to call the Police and suggest they felt the crew concerned was "unfit for duty", who is the arbiter of competence?
Or can you only be convicted of the second offence kind of "retrospectively"? i.e., only if you've had a chance to demonstrate your impairment so to speak?
Curiously.