Reasons for poor ear formation?

So I know underproofing and a shallow slash can lead to poor ear formation in a loaf. Poor steaming could also do it. Are these the only things that can lead to poor ear formation?

The reason I ask is that I was making dinner for my folks last night and so I had to have fresh bread. The basic formula I use is like this:

70% AP

30% whole wheat

66% water

2% salt

1% yeast

This time I mixed the dough together without the salt or yeast, then added the yeast and folded it in an hour or so later, and another hour or so after that I added the salt and folded it in. This made for a very interesting experience, since the salt drew out some of the water. I ended up with something a lot like a laminated dough. Anyway, I kneaded it all back in and shaped it just fine, then proofed the loaves in the oven for an hour before baking. It was a pretty cold day.

I preheated the oven to 425 and baked the bread for 30 minutes with steam, turned the heat to 375 and backed another 10, then finally at 325 for another 10. The temperature on my oven is off and my baking stone broke into many tiny pieces during the move, so the numbers I set the oven at are 25-50 degrees higher than the temperature I end up getting. Anyway...

I cut three slashes into each of the two loaves with my kitchen shears. I've done this before with no issue, I like the way it looks occasionally. Usually I just use my bread knife or a razor.

I suspect I underproofed the loaves because I got a bit of tearing on the bottoms. Still, the crust crackled wonderfully on each and the crumb wasn't dense at all. I can post a picture of the remaining 1/3 of a loaf when I get home. Nearly all of it was eaten immediately and my parents took the other home with them, so flavor and texture wasn't a problem. The problem is only the appearance for my own personal gratification. The ears, quite frankly, sucked. They were tiny, it looked like the dough had started settling back into itself rather than separating as I have come to expect. There was obviously some disturbance there, but nothing like I normally get.

If anyone can either confirm my diagnosis of underproofing or provide an alternative explanation I would very much appreciate it. If pictures are needed I'll post them in a few hours when I am home.