My Chrome tab goes to "Aw snap" as soon as I hover anywhere on those images. Tree or not.
Mine did it as advertised. Not sure why yours is different behaviour. The code and the rationale behind it is really simple too.
yield '[ohai]: http://www.berkeley.edu/'
yield '[onoe]: http://www.stanford.edu/%%30%30'
That's the two lines that replicate the bug. The bears are linked to berkeley, and the trees are linked to stanford. And I'm sure there's something behind that.
Those are arranged by a python script into arrays with the images, using a map file to position them in markdown. So with it being that simple, not sure why it wouldn't work.
One caution that I found out the hard way... if you do this too many times, you can corrupt your chrome for any other tabs you have open. That's why they said close all tabs, even though it only messes with one. After that, since I had amazon up, when I tried to browse, Amazon would lock up my machine. I cleared the cache for the last hour... and it started working again.