As an aside, it seems Renato was quite correct about not running a half marathon PB close to the marathon;
Tergat ran 59:10, his 3rd best ever, and suffered today with 2:11:38.
You're right. There could have been no other factors underlying Tergat's 2:11 - it had to be the PR half, case closed. I love the deep, analytical minds on thius board.