I think based on this pic he's taken one too many tuna tins to the head.
This photo was taken at 78km from the Calga drinks stop. You can see Horrie in the background. This was all part of the congo line where runners were passing and repassing each other with brief acknowledgements. I guess wondering if this is the last time he passes me or can I get by again going through their mind.
I suspect Brendan was just relieved he had a free hand as he had spent 77.5km with a water bottle in his hand and felt free since I had taken the water bottle ahead to fill it up so he could run through the aid station.
I was surprised to see Brendan do this as this part of the course was quite tough and they were all digging in.