Why you shouldn't step over a closed guard... (at 3:40 on the video)
Yes, purple belts make mistakes too.
Why you don't step over a closed guard.
Why Boston Crab needs to stay illegal in grappling competition.
Disclaimer: even I couldn't write the sarcastic comments I came up with. This injury could have been tragic. Thankfully, rumor has it that the grappler is currently recovering from the injury