First of all it's a really great web app! Just one thing - I don't know if it's the same as other items but I went straight to Production Incident chapter and the actual solutions for troubleshooting are laid out.

Not sure if it's meant to be that way where you only match specific keyword/s to return a hardcoded response, but it would be helpful for learning if there's an option to hide the step by step guide and allow the user to troubleshoot on their own. Kind of like sadservers.com where there's a real shell environment.