So the jQuery regex, for comparison, is

  (^|/)jquery([^.]*)(\.min)?\.js$

while the Bootstrap regex in question is

  (^|/)bootstrap([^.]*)(\.min)\.(js|css)$

with the ".min" not optional. (Looks like this was the intent [1]).

The 68.9%/26.5% percentages match the 130k/50k ratio of bootstrap.css to bootstrap.js, so it looks like only bootstrap.min.js is being excluded?

[1] https://github.com/github/linguist/commit/d5002ef06a9f346391...