In the  10 week training cycle leading up to this he only went 90% or more of his previous max for 2 weeks.  However, since the training cycle was based on a very conservative number, he never crossed 87% of his true max the entire cycle.  A PR is a nice surprise when you haven’t been training very close to it.  The stronger you are and the older you are the less you can play with near max weights on a regular basis. Train smart and you can continue to progress.