GitHub team seems to be VERY unprofessional. 15 hour outage means ~99.82% availability which is extremely bad. 9 hours ago they also told that they would fix the problem within 2 hours... still not fixed!!!
Doesn't happen in practice and usually the whole thing is just blamed on "process" with subsequent "process changes".
I helped manage a hosted DVCS and CI system in my previous job, and do you know what we would've called an outage that happened at 7:00PM and had recovered partially before start of business?
A Tuesday.
Wait for the RCA to come out before throwing any stones.