Falcon,
I do see what you've done there. As I said, I don't know the exact phraseology the ATCO used.
What I do know is that I say 'via K taxi stand.......'. I make no mention of Z2 or Z4 crossover, why would I? If i want them to take the crossover i'll say 'via K, Z2 and Z, taxi stand......' And yet occasionally some pilots take it on themselves to take the crossover without being given the instruction to do so.
If the crew were downwind abeam a 10mile final and the radar ATCO gave just a descent clearance, would the crew then take it on themselves to make a base turn to save a bit of time? Of course not, so why should it be any different on the ground?
If the pilots follow the instructions they're given, there should be no problem. If uncertainty exists as to what the ATCO means, then ask.
Simples.
Although we may keep an extra beady eye on certain airlines or airlineskis, it's fair to say that we wouldn't tend to expect issues like this from the likes of Lufty, BA, KLM etc.