But still, what the gp says was that a wooden log would have a food label with a high calorie content. That is not correct.
Was the original comment edited? As it reads now, the GP makes no mention of a label, only the factually correct statement that a log "is several megacalories" (ie, hardwood releases about 20 kCal/g when burned) but "you'll starve eating it" (ie, human digestion is not able to make use of this energy).
You are right that a current nutritional label would not show the log has having any significant number of calories, but the GP's actual post never said that it would. What makes you visualize this non-existent food label and then claim it is incorrect, as opposed to accepting their statement as written?
I also do wonder about the calories in ethanol. Apparently its immediate metabolism does produce a few atp, but the fact that hangover cures are universally high calorie foods suggests that the downstream steps might be endothermic or rate limited by fat, if that's even possible
We don't use the bomb calorimeter today, but we still use the Atwater system (with a quick tweak for fiber) for those "nutritional components." All that means is instead of burning the food ourselves we're looking at a table that the guy who burned the foods created... with his bomb calorimeter.[1] The only reason we're marginally better now is because we're starting to take into account digestibility (e.g. Carbs have non-digestible fiber subtracted before the calories are calculated).[2]
[1]https://www.scientificamerican.com/article/how-do-food-manuf...
[2]https://en.wikipedia.org/wiki/Atwater_system#Modified_system