My little pumpkin started rotting a few days after that blog post. I'm not sure what went wrong. Maybe blossom-end rot, although I have been keeping the soil pretty evenly damp, mulching heavily and there are tons of broken eggshells in my compost providing calcium. My other guess is that I didn't pollinate the flower well enough. Who knows, though. I also think the 3-day heatwaves we've been having every other week might have done the pumpkin in. I don't think squash like that dry heat.
I'm not giving up on my pumpkin patch dream just yet. The vines keep growing and making female flowers. Hopefully if the weather stays below the mid-90s from now on, and I can keep the plants well-watered and fed, I'll get a few more chances to grow my son's Halloween pumpkin. I also read somewhere that coffee grounds are a good source of fruit-making potassium. So, I've been dumping out the French press onto my squash hills the last few mornings. Whatever works!
As for the one that didn't make it, I managed to find a use for it: chicken treat.