ORIGINAL: Nathan King
True, not forming a pack, while a good practice, will not cause all of your batteries to immediately vent. He probably had a weak/bad cell or a short.
Hitting it with a 4 amp charge for the first charge will vent cells in many packs.
Now if he had started with 1 or 2 amps it probably would have been fine without a form charge. But form charging is the way to go.