In that case, you probably need to implement a custom include processor. You could detect when you want to ignore the include and return the include statement itself, thus restoring the original line. You could detect it perhaps by looking at the language on the source block (e.g., [source,asciidoc]) or the extension of the target (e.g., .adoc).
Aside from that, Asciidoctor doesn't have any special facility for recognizing and ignoring its own syntax.
-Dan