Can I invoke discardRequest() in JxioSessionClosedException's handler?

[lynus]

According to JXIO API doc for ServerSession.sendResponse():

org.accelio.jxio.exceptions.JxioSessionClosedException - if session already closed. In case exception is thrown, discardRequest must be called for this message after SESSION_CLOSED event is officially recieved.

Does it mean that the message that failed to send due to this exception can only be discarded in onSessionEvent()?
My problem is, in my program, ServerSession might closes before another thread calls sendResponse(), which means discardRequest() might has no chance to be called in onSessionEvent().
Can I just discardRequest(msg) in JxioSessionClosedException handler?