Chris, I'm sure you could knock off quite a chunk of time to allow for the hot sunshine and congestion. I know from a few runners locally that you weren't the only one a bit disappointed with their time on the day. You can be pleased at being well in the top half for your age group. Glad to hear your foot is better.
In complete contrast to the track race yesterday I did a fell run this morning, my first. It was only 4.6 miles but very hilly. Mostly on rough grass tracks, stony farm roads or woodland paths. I felt surpringly good and was pleased with my average pace of 8.35. That ranged from 6.45 to 9.55. Four others were there from my new club and I'm gradually getting to know a few people.