DFC,
It's all very well quoting from MATS Part 1, but we both know the world is not so black and white.
I've seen many crew assume the conditional aircraft was the one that had already passed them on the runway, not the one still on final. I've also seen ATCOs make mistakes and misjudgements.
So what would you do if you were waiting to cross at the midpoint; one aircraft had just touched down but was yet to pass you, there was another 2.5nm out on approach, and I'd just given you an 'after the landing, cross......' clearance. Would you know I meant after the at 2.5nm, beacuse that's what MATS Part 1 says? Would I be safe to assume all pilots are as familiar with that document?
Not sure why you think this is all rather amusing, some of us take this sort of thing quite seriously.