Lithocarpus cleistocarpus - why all these dead leaves?

I'm having trouble figuring out what I'm looking at here on the Lithocarpus cleistocarpus. I didn't seem to take a photo of the whole tree, but it's entirely covered with dead-looking terminal clusters of leaves. And these leaves looks different from the older leaves, with prickles on the leaf underside midrib and I think the twigs, which do not occur on the adult leaves in my photos,

and I don't see prickles on my photos from July 2012:

or last July.


There are new leaves coming on branches that do not have these leaves:


Did something happen last year that caused all the new leaves to die off? I don't think I'm being fooled by some unrelated vine - the first photo shows the dead-looking area growing right off the end of a branch of green leaves.

 

Looks like a late frost has killed these outer shoots / shoot tips.

 

Yes, looks like the newly emerging leaves are damaged. Considering our weather, maybe drought stress. The ground has been very dry at times for a plant with newly emerging leaves. The prickles may become more pronounced as the leaf dries, just a guess.

 

This Lithocarpus cleistocarpus didn't look so bad today. The new leaves have opened. The old leaves are so beautiful with the dark tops and light undersides.