Gonzo,
Perhaps you can explain this to me....
I have a CTOT and I get to the hold for 36R in Madrid. There are 5 aircraft ahead of us, all Iberia. However, instead of putting us to Y2 or Y3 ( an intersection approx one or two hundred metres up from the end, we are told to queue behind Iberia. When I reminded him of our slot, his reply ' don't worry, we have and extension!' an extension until all the Iberia have taken off before us.
And before you ask, no, they didn't all have slots!