His post was an expression of the physical discomfort that he was experiencing due to an acute form of pathology known as "filmmaker frustrations." You'll be attacked by it at one time or another... probably soon. It happens.
Looks like you're overcoming this disease quite well...
1. What do you mean by they? You were hiring more than one make up artist? who already knew each other? (there is a problem right there, that I cannot fully explain right now. Maybe I'll write about it another time)
2. Did you interview these people in person before your shoot?
If you answer "yes" to number 2, then I don't have an answer. It must be some strange case particular to the British Isles.
If the answer is No, then interview them next time. If they show up for an unpaid inteview, that's a guarantee that they're not faking it, and will show up on payday.
Directing is a special form of human mind game
. Not only do you have to know about normal human beings, you now have to learn about a special sort of human being, who is strapped for cash, but will pay to be in your seminar, and won't show up to your free seminar. It's called ... I don't know what it's called, but some psychology student should do a pHD thesis on it.
Cheers. Better luck next time