So I checked our web server logs around that time and didn’t find any server errors or slowdowns at that moment. The traffic there was mostly automated crawlers fetching old URLs and getting 404s. I think maybe this time it was a network hiccup rather than a site issue.
I'm going to see about blocking a couple of those crawlers that are not important and more likely to ignore rules we set. That may be causing some temporary hiccups at times too, so if that is it, it might smooth out.
Thanks for posting about it.