dunno, honestly. we'd have to find and ask somebody who's knowledgeable enough and removed and inspected a provari pcb. i haven't. i like my provarii working and under warranty. both of them.
but often times with modern electronics, having a bettery in it while it's turned off, only supplies energy to a very small portion of the board. a very low current portion of the board that's a lot less likely to short when it's wet.
you bring up a good point. it would take three tests to impress me. one with battery installed. one with battery installed and power on. last but not least, one where the battery were installed, power was on and the button was quickly taped down and the
mod was dunked with an atty still sizzling.
if it passes those tests, it's indestructible. if not, it's simply modern electronics. i used to send televisions, watches, radios, and all kinds of electronics to be dunked and ultrasonic cleansed all the time. mineral free water won't hurt most electronics and most water won't hurt most electronics if they're not powered on.
i've freaked quite a few people out by putting a hose to their electronics to save them after they've spilled their drinks on them or dropped them in the toilet. it's rare that something goes wrong if they weren't powered on. even then it's almost exclusively that whatever offending compound or liquid is still in the unit when it's powered back on that creates the issue.
methinks it's highly likely that p.opus' e-lvt was still wet somewhere inside when he powered it on.
ADDIT: to be honest, if p.opus used regular tap water... especially if he has hard water... i would highly suggest he do another dip and rinse very will in distilled or deionized water to wash away any minerals he may have deposited on the bus lines of that pcb. when electrical current is supplied to a circuit, ions can form a chain and they'll attract each other to create a short. it may take time and build up, but the less there is, the better.
honestly, i'd be highly interested in the specific gravity and/or general hardness of the water that was used. you see, water itself is known to be an insulator. it's the minerals in the water and the fact that water being a carrier and a liquid allows them free movement for their ions to create a chain that makes water a conductor. it's not the water. it's what's in it.
ADDIT_2: it's also worth mentioning that lithium cells are water and air tight. if oxygen (present in water and air) were to get in, it would react with the paste in the cells violently. so, the battery from the e-lvt and the one in the provari are still perfectly good cells unless p drained them properly for disposal.