I'm familiar with the regulations as posted but I can tell you some 121 & 125 operators have relief on the 10% so that only certain parts of the total time have the 10% applied. I believe DAL may be one of those airlines.
The above was not a part of the original question and I was simply looking for an equivalent reg within EASA. Apparently they treat this differently and since I'm working on an EASA project, that was the purpose of the question. I'll do some more research and report back.