Ah-ha ... so this is where I can find your RR. I was totally wondering what you were thinking over that first 10k when I saw the split posted on FB. I'm glad to hear that it was just a timing error and you weren't actually running 7:15s.

Now, I think you wrote a really nice RR with some good self-reflection on the performance. Others have added the combined issues of hilly course and temperatures and that's where I'd place my money on the fall off from your goal. Running at GMP is NOT easy ... at least for the full 26.2 miles. It really takes the stars to align in order to pull off a peak performance in the marathon. Overheating and dehydration cannot be overcome ... now if I can just remember that and take my own advice.

I think you ran a fine race and though you didn't hit your "A' goal, I'd take a PR any day. Kudos on a fine race and a nice report. I think Moth's advice is solid regarding GMP and specific training to push the body support system. I think I maxed out at 15 MP miles segment in a Pfitz long run and I often throw in several "finish fast" MP miles to other long runs. However, even with those training miles the effects of heat & hydration can't be overcome.

Rest up and take this race as a springboard into your next training cycle for the fall.