Did my tree or shrub survive the winter?

This winter we spent over 100 hours below freezing which hasn’t happened in Dallas for a couple of decades.  An easy method of checking to see if your plants survived is to take a knife and lightly scrape the bark of the small limbs toward the tips.  If it’s brown like the one in the smaller photo it probably didn’t survive.  It’s April now so you should see some buds.  Notice the buds on this tree are brown.  They flaked off when I touched them – another sign of a tree that’s dying.  If you look at the larger photo you’ll see where I scraped the bark off of the limb of a holly and just under the surface it’s bright green.  That’s a healthy plant.  We’ll have to replace the dead oak tree though.