GitHub integration allows automatically creating Case Events in FogBugz cases when git commits are pushed. You would like to extract these git commits (aka case comments/posts/events) via the FogBugz API.
Retrieving GitHub commits from FogBugz cases is not available through the regular search API command because internally GitHub comments are stored in a different structure (not as plain case comments).
Currently, you can push commits from GitHub to FogBugz using the integration but there is no API or process available to pull GitHub commits.
This has been considered as a Product Enhancement and submitted to our internal New Feature database for consideration in a future product release. Please note that we cannot provide timelines for the release of product enhancement or feature requests.