Egg on my face

The other day I bought pre-cooked shelled hard-boiled eggs to eat for quick snacks at work. You might think that is disgusting but the are filling and don't take much time. I grabbed an egg for breakfast and put it in the microwave for 10 seconds just to warm it up a bit. I brought it back to my office, shook some salt on it and bit into it. The whole egg immediately EXPLODED and steam and egg yolk blasted my face.  To say the least I was very surprised. I asked other people in the office if they knew that the egg would possibly explode. Only one employee said "of course it will explode, don't you know eggs heat from the inside out?" I thought it was easy for her to say after the fact. Let me know - was I an idiot to not expect the egg to explode? It burned my face just below my eye. I called the manufacturer to tell them they should put a warning on the bag and she said that they had actually just changed their packaging to include a warning.