HTTP 429 responses generally mean rate-limited.
Since you provided a hostname, @mrcportillo , I could look for rate limits on your domain and what I see is that your site has basic authentication on it, and we will absolutely block requests from your IP for awhile, if you fail to authenticate requests from the same one enough times in a row (which could happen a bunch of times, in case you reload a page with bad auth or even have a single page with a dozen links with bad auth - most likely in Safari which has some difficulty in passing your Basic-Auth credentials automatically through on XMLHttpRequest calls, for instance). I’d guess that is what happened to you.
@mattalbrecht I assume you probably don’t use basic auth protection on your site, so if you want to tell me the URL and confirm when you saw it, I can try to understand what happened there.