The flow uses an internal redirect to handle an external request. This means that the propagated exception is only catched by the top-level Cocoon object which outputs the default error page (if configured to do so). So we can say that the behaviour of not executing error handlers for internal requests is not suitable for internal redirects.
Can you clarify something first. If exception has happened during <map:call function="..."/> processing (which called some other internal resource, but it does not matter right now), will sitemap catch this exception and proceed to the <map:handle-erorrs/>?
If yes: what's the issue than? Use handle-errors! If no: we clearly have the bug of enormous size! :)
Vadim
