Right yesterday me and a freind were doing this, then later on another freind joined and I was messing around sniping with him. Then I was showing my friend where to jump through to get under submarine (with my sniper class, stopping power, steady aim and intervention. ) And I just jumped in normally and got through....
I have a feeling I know how I did it, and think it could be very cool new glitch to getting through death barriers, such as on afghan and highrise. Anyway I probly need someone to help me out, so add me on PSn iJoshh.