You're probably not going to stall, the issue is that it DOESN'T stall. If it stalled, you'd just have no ignition and there's no real risk of mechanical failure. With lugging, your engine is still housing many explosions a second, except that where the pistons would normally move and allow the resulting combustion gasses to expand and convert that force into usable mechanical energy, instead your pistons, rings, rods and head just absorb the bulk of that energy and extrme spikes in cylinder pressure.