I have seen similar bugs in the systems I oversee because network libraries love to retry requests without sane limitations by default. But I never saw them make our rate limiters sweat. It's slightly more annoying when they hit an API which actually does some expensive work before returning an error but that's why we have rate limits on all public endpoints.
I also guess that the webapp is the least of Twitters traffic and the native apps probably don't have this problem.
Seems like either my quota reset or they changed the policy because I’m able to access the site again.