What does this have to do with the OPs issue ? He never said he hit anything , never said speed or RPMs was his problem. Motor was running good, alarm went off and it shut down . Now it might help if he posted it in the correct forum on this site.That jolt may have been the final straw and you have a spun hub (no longer enough resistance between the hub/rubber sleeve and prop itself)
Fairly simple repair at a prop shop if that's the problem. If you have a spare prop, try that out. If not you can place a mark on the hub (next to the splines) and an ajacent mark on the prop itself. Take it out for a little "spin" and see if it comes back with the marks out of line...