New infomation, article edit would be good to include this info.
From The Lost Media Wiki
In a new Tested Q&A (https://youtu.be/cS7mlM5yy1A?t=2260), Adam describes more about the incident. They mention dubbing the mouse 'Killer', said mouse being fed to Jamies pet snake Gomez (the same snake from the blueprints in series one of Mythbusters) and most importantly, more info on what happened to the tape this article is referencing.
Adam had a rough copy, showed it in 2005 to the institution talked about in the article, and Discovery rang him and ordered him to destroy the tape afterward. I'm guessing they did the same to anyone else who might have had it. Maybe put how Adam describes it as a quote, rather than a description?
It's therefore pretty unlikely that footage will be found.