Unfortunately I don't think the engine shut-down was because of the low coolant level. It could however, have a new electrical issue because of the coolant leak.
My 2008 Topkick work truck did the same thing. About 10 seconds of warning noises, the it just shuts off. Completely. If only became became more and more regular, and eventually I got pretty good a rolling re-start. We took it to both Allison in Junction City and to DSU-GMC in Portland. It was an intermittent electrical issue, and we replaced the engine main harness, the PCM, the transmission harness and solenoid pack to no avail. We eventually ended up removing the body and scrapping the chassis. The downtime and potential liability was just too much.
I would definitely trace the path the coolant might have taken, and clean everything well with water and electrical cleaner. If I remember right, one of the chassis main harness runs below the bottle. Plus any harnesses downstream and aft inside the frame rail on that side, since coolant can blow a long ways. I'd even suggest pulling apart any downstream connectors. CRC makes a good spray cleaner for this kind of stuff.
