Is this the Toronto Incident mentioned earlier in the comic??? Probably. But as for what led up to Jeff stopping a train, I’m afraid I can’t reveal that at this time.

Also I’m not sure if I conveyed this properly, but Jeff’s expression in the last panel is supposed to be him fighting between bragging and underselling himself. It’s something I fight with myself, it can be hard to know where the line between confidence and arrogance is.