That sinking feeling is the worst. Scratched the blade on my good marking knife last year the same way, leaving it out on the bench. Now everything gets wiped down and put away, no exceptions. Really teaches you to slow down and respect the tools.
Man, that awful sound when metal hits something it shouldn't. It just sinks your heart, especially when it's a tool you've had forever and trust. Jake must've been gutted. It's the worst feeling, ruining a good piece of steel like that.