Complacency, unit passed a neg before the dive but has a known poor oring seal at one joint. if it gets knocked it can leak. in this case it started leaking within minutes of getting in. I always get a bit of moisture in the exhale one way valve that gurgles from spit, but usually takes a while to build up. Was getting some gurgling straight away (oring is at the top of this hose) and was deciding whether it was leakage of just build up. Then I got busy with failing cells and checking what they where doing, then it was all over red rover. Been looking to change out all o-rings on the unit for ages, just struggling to get parts for it. Now have no choice.
Matt