Reality is that with a 4 hour delay in BAC testing, he shed (through normal excretory and metabolic processes) the equivalent of four drinks.
For most folks, each of those drinks is somewhere between .02 and .025 blood alcohol percent (it depends on body weight), which means at the time of operating the vehicle (working backwards and generously allowing 45 minutes to become post-absorbtive, as if his last drink was a shot done on the way out the door), that delay reduced his BAC by.06 to .0825, which means at a minimum his BAC at the time of arrest four hours before being tested was in excess of .14, and quite possibly much higher (they only note it was in excess of .08 at the time of testing, not how much so).
For most people, that's fairly schnockered, or at least well into 'tipsy', and no state to be driving, (for some, it's purt'near puking drunk) but with lots of practice, people develop some resistance and remain functional beyond legal limits, albeit impaired enough you would not want to share the road with them.
Blowing through a traffic signal indicating he was supposed to stop and being involved in a crash would support that conclusion.