Freelander 2 (LR2) Freelander 2 clutch failure

So I've just crossed Europe to Poland without a hitch, second time the FL2 has done this run with me but on Wednesday, in city traffic I put my foot on the clutch and it went to the floor... Oh ****, but as it was driving I managed to get to the side of the road, lucky as Warsaw is unforgiving if you block the traffic.. Anyway, into a friends workshop and clutch out. badly worn DMF has caused slave cylinder to fail.. New clutch ordered and will be here tomorrow.. Its not given me any warning at all, but I would say its been a bit rumbley recently but I'll know better Monday or Tuesday when its back on the road..

How did a worn DMF cause the slave to fail?

Movement of the pressure plate I assume...The springs chew away at the thrust surface it would seem, the result is enormous once it starts..