I'm going to have to side with ASKAR on this one; it just doesn't sound like there was time to stop & let the wolf get closer. The wolf was on him once he noticed its presence and I'd wager most wolves are capable of keeping up with, and easily overtaking, most cyclists (I believe wolves can hit upwards of 60 kph). Note the following:
This surreal moment of shock and confusion passed immediately was the “dog” lunged for my right foot and snapped its jaws just missing my pedal.
WOLF!!! At this point I received the biggest jolt of adrenalin I have ever had in my life. Without so much as a thought I shifted my bike to the highest gear possible, started to mash the pedals like never before, and reached for the bear spray in the handlebar bag. I threw off the safety and gave the wolf a quick blast in the face which served to slow him down so that he was now 20 feet behind me but still not stopping. He hung back for maybe 20 seconds and then raced forward and attacked my panniers, in the process ripping my tent bag and spilling my poles onto the highway.
Based on this, it sounds like stopping (without deploying the bear spray) would indeed have resulted on the wolf being on him immediately. It sounds like the only way he was able to stay ahead of the wolf was due to the spray's ability to at least slow down the wolf.
I think this is one of those scenarios where both bear spray and a firearm would've provided the best chance of survival. It sounds like there may have been an opportunity for a proficient individual to use a firearm if they first used the bear spray to get some distance between the attacking wolf and themselves. Alternatively, without spray, an individual with only a firearm likely would have had the unpleasant task of trying to ready and use the firearm with the wolf already in contact with them.