When the December 2014 git vulnerability was disclosed to git maintainers (I can't find the CVE number now, but this was the github blog about it:
https://github.blog/2014-12-18-vulnerability-announced-updat..., and this was the hn discuss then:
https://news.ycombinator.com/item?id=8769667, tl;dr is git only checked and protected all lower-case .git directory from overwritten by clone/checkouts, which will becomes tricky when it's used on case-insensitive fs), they contacted both Microsoft and Apple to make sure that they fixed all the corner cases of their case-insensitive file systems. Microsoft was very cooperative at the time, pulled in someone from NT kernel team to make sure that the fix covered all the corner cases; Apple, on the other hand, didn't response. Even after the patched version of git is released, Apple didn't do a hot release of Xcode tool (which is how they distribute git officially on Apple's systems). They only included the fix on their next scheduled beta release of Xcode.