Hey there,
I randomly stumbled upon and found a potentially obscure issue.
You can add any amount of forward slashes in-between url fragments, and the page will keep working and resolve the page.
See example:
https://www.xxxx.com////////events-results/ppv-special/////njpw-world-tag-league-2016-finals
You can add as many slashes as you like in any of the URL fragments. It will keep working and resolves the page.
But apparently, Googling around, this is a "normal" behavior: https://stackoverflow.com/questions/10161177/url-with-multiple-forward-slashes-does-it-break-anything
So I guess nothing that has to do with sh404sef. But I noticed it will even keep those slashes in the canonical URL that sh404sef generates as well. Eg. check the canonical URL in the HTML of the page I sent you.
Let me know what you think!