A hair line of unfused metal running the whole length is wild, that means the thing looked fine on the outside and was basically two separate pieces of steel sitting next to each other. I can't believe a foreman would push guys to skip the root just to save time, that is a failure waiting to happen. The cut section under magnification is what does it, you can argue with a guy about a visual all day but you can't argue with a cross section.

It's like how people buy fancy gym gear and then just walk every day instead. The simple version wins because you actually do it.

How many cubes were you dropping at once and where did you put them? If you stacked all 3 in the same spot every morning, that's basically pouring a shot glass of water into one corner of the pot. The rest of the root ball stays bone dry while that one pocket turns to mud. Did you poke a finger in a few inches over from where the cubes sat, or just check the one wet spot and assume the whole pot was soaked?