In the Fire Service we have a saying (perhaps you have it in your corner of the world as well): If there's little to be gained, little should be risked.
I'm a bit surprised at the number of folks who seem to have no problem at all with the concept of diving on a tank with unknown contents...even if it's just a "pool dive." In my professional experience, people can die in a swimming pool just as easy as in an open body of water. It's also erroneous to assume that a cylinder would fail before the oxygen content fell to a point that would not sustain life.
Coll, glad your experience went ok. At the risk of sounding harsh, the judgement exercised in this decision is, in my humble and unsolicited opinion, questionable. Just because "his boss said to" wouldn't comfort your family or care for that adorable dog of yours if something untoward had occurred. An unrelated question: Does your employer's insurance cover diving activities in the workplace? I can't be certain, but had something happened, investigators may well have heaped a substantial portion of the responsibility for the incident on you for being usure about the tank but using it anyway.
Risk vs Benefit: It's an analysis that can keep you alive.
Dive safe and see you down there.
