Wow, that code is entirely unreliable. It just detects your browser's viewport being outside of some threshold of a "normal" aspect ratio and then just blindly assumes that means the devtools are open. The only devtool it can actually detect is Firebug. Everything else is nothing but a blind guess based on the size of your viewport. I'd be astonished if anyone used this code for anything serious.
That person churns out a staggering amount of code so it’s not a surprise I guess that the bit about “does this code actually work” is probably lower on the list of concerns
