batch applied: "Directory not empty (66)"

[Raymond Keller]

"rsync  version 2.6.6  protocol version 29"

In my source I have a directory that changed to a file.  I know this
requires --force or --delete, but using --only-write-batch I get no
error until I attempt to apply the batch.

This confused me for a bit.  Is this intended behavior?

Also, unrelatedly, when rsync refuses to apply a specific change
from a batch due to the destination not being in the right state, is
there any way to get more detail on what aspect triggered the
refusal?

Thanks,

RSK