Mystery Tree/Bush Zone 7b has nuts or drupes or something!

Here's the mystery:
A tree about 3 meters (~9.8ft) tall that has been pruned into a hedge at the house I am renting in Williamsburg VA (zone 7b). It has glossy serrated alternating leaves, large flowers on the ends of the stems, and green 1.5" diameter nut-like fruit (or maybe true nut) with 4-10 seedy/nut meaty sections. The brown covering of the seed is hard yet thin. Squirrels have been eating it. Any ideas what this is?

EDIT I just stared at the leaf picture again and thought the leaves looked a lot like a camellia. And appears to be Camellia oleifera...

I agree with your edit - the first photo looks like camellia leaves/flower bud, the second like camellia seed pod, and the third like a camellia blossom. Good call!