If your SPG came off you had at least 20 minutes (with a full tank) before you were OOG. What's the hurry?I’ve been in this situation. My SPG came off 45 minutes into a dive. My buddy ignored my OOG signal, but signalled he wanted 2 more minutes before surfacing. I reached over and took his AIR2. Now I had his buoyancy controls and we were going up. We did a deco stop before hitting the surface where the boat was waiting. They knew there was an issue because the sea had erupted from my leaking hose. Before my next dive I had replaced my AIR2.
And why did you replace your AIR2? It is a fine system for you, just not to give to someone else.