Airline Passenger Investigated for Vaping

Tiger Airways has pulled in the Australian Police to investigate a passenger over 'violating their no smoking policy', because he vaped on the flight. This could be called an extreme zero-tolerance policy, which certainly would make sense if it constituted a risk in someway to the aircraft.

But does merely vaping and not even charging the thing constitute such a major threat? Apparently so. They list three reasons, the lithium ion battery, the risk of setting off a smoking alarm, which I have to imagine are somewhat more sensitive on an aircraft than in ones home, and that it upset some other passengers. I'm wondering though if the risk of the lithium ion battery is not somewhat overblown, much of the cases where they have blown up are when they are charging with incorrect charging units, and what is the risk of people using other lithium ion devices? For the time being it's safe to assume, unless the airline says otherwise, vaping is not an activity one should perform on an aircraft.