Fix comments claiming to ensure reliability when in reality there is
only a small likelihood of the message being received.
Broken by fa85527baf / refs #2420 which was a preparation for a3e1c68b9a
/ refs #2373, which hence didn't actually work and was circumvented by
9b136a45fc without clarification.
Might have caused #3643.
Differential Revision: https://code.wildfiregames.com/D1557
Reviewed By: Imarok
This was SVN commit r21837.