It's funny but not the first time I have heard someone come back from illness/injury to run a PR. I know two guys from the school my son transfered out of who always go very easy before races. If I told you how little mileage one of those guys runs and who he is, you would absolutely not believe me. Reed would benefit greatly from a strength program. My son (like Reed) has a very demanding major, making it difficult to get to gym, so he does an all body weight routine of exercises. He skips doing them here and there but does them for the most part. Look at Leo Manzano he does basic old school exercises and shares them on Flotrack, because they work.
I think planning an intelligent taper is smart. Or you could expose yourself to cold virus 3 weeks out and run taper in disguise. So Reed found out that a body weakened by virus and forced to rest, was then strong enough to run a demanding race and PR. Maybe Reed's aversion to my suggestion of taking it a little easier before a race was just all in his head. Think what he could have run if he hadn't gotten sick and just rested better.