Halo 2 > Halo 3 > Halo 3 ODST > Halo Reach > Halo CE
Based on campaigns.
Posted by: Multijirachi
I had this problem as well, my friend used it against me until he told me what to do.
After you lunge (RT), immediately hit B. Keep button smashing B if you continue to fight. It takes a bit of practice, but you'll get it eventually.
If this doesn't work, lag or he was host.
Thing is it happens ever match of swords. Perhaps i will try that B trick, or maybe it is Halo 3s Poundland servers