You sure it was https? For a short time they blocked port 80 specifically so git:// and https:// would be able to work.

Yeah, I had one https:// clone stop in mid-download. I repeated it immediately and it stopped midway again, I tried again after half an hour or so and it went through.

This was before they disabled port 80, so I expect this was resource exhaustion, the smart-https git service wasn't completely isolated from the DDOS target.