Out of 1,996 files copied, there were 3 missing files. They were all .exe files.
Many other .exe files were, in fact, copied. Two of them were the SQLAGENT.EXE and sqlservr.exe.
The services were down at the time, but I'm thinking that somehow there was a handle on these
and that that was the reason they were not copied. I should have thought, though, that the
Netbackup job copying the drive should have reported the failure to copy these. I'll have to ask
the Storage guys about that.
Anyhow, the 3 files were manually copied and all is well.