if anyone, I s'pose most likely seen by a bird

Odd... but when I was just about to pull out of the parking lot after work today, what should fall onto my car's hood... but a little egg... splat. Shell and all. Not the usual splat we all see... so I got out and looked up into the tree. I couldn't spot anything, no nest, no chirpers, ... did a bird just lay an egg whilst flying? Not a teeny sparrow sized one, but not a big chicken sized one either... more like maybe crow sized, about an inch in diameter, and there are lots of crows in this lot every day.... but gosh, why?
Mystery of the day I guess!