I don't know if this is true, but it seems plausible that the bulb could have asymmetric strength depending on the angle force is applied. Glass does weird things! Case in point: Prince Rupert's drops.

Edit: Alright, this seems to be a myth. https://skeptics.stackexchange.com/questions/38262/can-a-lightbulb-once-inserted-into-your-mouth-be-safely-removed