For what it's worth: Crunchydata appears to have been using Heroku DNS in some way. We have a Heroku app with Crunchy databases, and our Crunchy dbs became inaccessible shortly before the app did.
Craig here from Crunchy, we do run some small pieces on Heroku, but during the DNS outage saw no interruption of databases and they all seemed to be available and up. Please do feel free to drop us a note and we'll happily investigate if something did occur there.