Sigh, don't know what happened. Tried Charlie's Easiest Bread Ever again, chilled the water, chilled the dough in our makeshift cooler, managed to get it into the fridge before DT rose above 24C.
Took a peek 3 hr later, and it had overproofed and collapsed! Considered trying to "save" it with some folds, but the coating would have been ruined and the seeds might have clumped up inside as they had in the previous loaf.
Finally decided to just bake it and hope for the best. Cranked up the oven to 260C and popped it in before lowering the setting to 180C. Amazingly, it did recover. When it came out 55 min later, it had risen again - not very high, but enough to give us a decent-looking loaf.
The inside was decent too when we cut into it 2 hr later. A bit dense, but not gummy. The flavour wasn't bad either, even though the cold ferment was so short. (Posting photos over at Baking Buddies.)
Anyone have any ideas why the yeast went on a rampage, despite all our efforts to keep the temperature down? Maybe we bought a mutant batch that was nuked at Chernobyl...
Well, we refuse to be beaten by a monocellular organism, so we're working out our plan of action for Loaf III. Kevin suggests halving the yeast, which should help. Think we'll also skip the seeds till we can pin down the process - if need be, we can try to save the "naked" dough. Hope Charlie will forgive us for stripping his loaf bare haha.