The damage on the trunk looks like sapsucker damage.  http://plantdiagnostics.umd.edu/level3.cfm?causeID=1228  Without more information we cannot say what caused leaves to turn brown.  We cannot see brown leaves in your photo.  There are a few old leaves that look yellow and will fall and this is normal.  All hollies normally lose old leaves every spring and the new leaves on the ends of the branches should be green.  To diagnose insect or disease we need a picture that shows a progression of ill effects.  vw