Torpedo egg with strange egg white

[LT]

This morning one of my girls laid a torpedo egg. She has been a bit erratic since a hawk attack and some recent thunderstorms. I needed three egg yolks for a recipe, and I thought the torpedo might be a double yolk, so I cracked it. The egg white was foamy inside. It had no odor and no other abnormalities, and since I needed just the yolk, I used it anyway. Any idea what would have caused this?