If it throws an error, then it's not conformant with ANSI SQL, at all.
ANSI says a DELETE that affects zero records is never an error.
I would be truly surprised if Oracle went against ANSI on something this fundamental.
If you are only looking to see how many records were deleted, most DB interfaces will give you that information.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.