I've had 2500 mah LIPO batteries "explode". I've had other Lithium cells vent. They aren't full of nitro, people. The SB isn't some cheap Chinese flashlight. I get the impression that some people think they're going to blow up like a pipe bomb if the battery vents, with shards of aluminum embedding themselves in nearby walls.. It ain't happening that way and the SB/BB has a heavy enough wall that even if it wasn't vented at all, I'd be shocked if it did much more than get hot and displace the switch a little, ultimately preventing the pressure from pushing the connector out of the top.
There's a ridiculous amount of paranoia going on about this. If a 2500mah 11V LIPO can vent and be contained in a small, unvented coffee can, the built in vents in an SB are more than sufficient to prevent any catastrophe. A battery explosion is not a high velocity, high rate of release type event like a stick of dynamite. I hope Chad doesn't screw up his SB/BBs by drilling unnecessary vent holes in them just to satisfy unfounded paranoia. If he does, I'll bet more people get liquid in there and screw something up than be "saved" by them when a battery vents.