They eventually got wise to it, however. Thus, whenever IRIS failed to
recognise somebody, they would simply say the equivalent of:

"That's your fault. Get to the back of the queue, you dog!"

It's their fault the machine doesn't recognise me (I was enroled, not
pretending to be enroled).

Ditto. When I was enroled I don't think the machine ever successfully
recognized me.

It's not a problem with the technology -- the iris machines at
Canadian airports work fine.