10K start pace

I wouldn't say that given the OP's history. He has only 1 race under his belt and even then it is at a questionable distance.

If you look at his training you will not see much if any running at sub 6 minute pace. He has developed his aerobic engine and just needs to practice racing and doing some shorter faster reps (e.g. mile repeats at sub 6 pace).

splits -

6:05, 6:24, 6:15, 6:06 (-31ft elevation), 6:23, 6:18

You started at workout pace for the first mile then couldnt hold it as you are not at that level of fitness. You are in low 38 to high 39 minute shape PERIOD. races dont lie.

Actually i totally agree regarding where my fitness is at. If you saw my original post my plan was to go sub 40 mins, which is in line with my training so far.
There was one workout which stands out and i assume in ideal conditions that is my max. Maybe i got little carried away due to that one workout. Still my race result was better than what I expected 3 weeks ago, so i am more than satisfied.

Since i am 39yo with full time job and 2 kids, i train for the fun of it and the result in training vs result in race is not that important and i do not have a problem being a training warrior. Actually it sounds quite cool.

Now i am focused on HM in October, where original plan is still to go sub 90 mins. After that i go back to training warrior mode.

Good stuff. This sounds like a very not ideal first race. Dark. Wet. Construction. Short course. But whatever, you went out and ran well. That's awesome.

I also think a 1:25 half goal is a great one given what we can see of your fitness. I hope the next month of training goes well and you get better race conditions!