Bookmarklet fails to run on site http://toplulz.tk in Chrome

[xaroth8088]

Steps to reproduce:

1. Using Chrome, navigate to http://toplulz.tk
2. Click 'start tournament'
3. Wait for all animations to die down. You should see two images side-by-side, and the announcer (if shown) should have gone away.
4. Execute the bookmarklet.

Expected results:
Stress test should run

Actual results:
Stress test shows "Testing __STRESSTESTBASELINE" and never continues from there. No errors appear in the developer console.

[xaroth8088]

Also FireFox, meaning that the bug may not be browser-specific.