If I'm not mistaken, Regina ran 3:59.98 indoors at age 39 right before she was busted. Lagat's 4:54 seems in the same ballpark as that. That's a 4:03 mile with a 55 extra lap.
I love Lagat and all the warmth he brings to the sport. But the comparison to Regina's performance at the same age troubles me, especially if he missed three weeks of training a couple of months ago.
Bekele ran 4:49.99 indoors and 7:25/12:49 outdoors in 2007. If Lagat runs 7:30-32 outdoors this year or sub 13:00 at 39, I say something is fishy.