Air has plenty of inertia - not nearly as much as water, but it's there. When a balloon pops, the rubber actually tears and retracts around the sphere, making a huge opening compared to the volume, and the air is not moving, so it doesn't matter, so that's a bad analogy.
I think surging isn't really the main issue in this case, but rather flow reversal - high velocity air has plenty of energy, and air exiting from the bov is moving at pretty high speeds.
Think more like letting a balloon loose to fly around the room, hitting you in the face - a little compressor wheel that weighs a few ounces has to do all the work to get air going the same speed in the opposite direction!
Also don't forget that at part throttle with a recirculated BOV open, air is being drawn through the BOV into the engine, partially bypassing the turbo and intercooler, and the pressure drops caused by each.
You may never notice the subtle difference from the driver's, but flow reversal through a restriction like the intercooler is generally a bad thing the place it will hurt is boost recovery on a quick upshift. The less air traveling backwards in the system the better.