I believe, (based on real events & theory) that with the horizontal style rails, especially if they're particularly pronounced toward the stem, that 'bow-steer' & 'roll' are directly linked.
Picture the style, with the rails staying horizontal, meaning, that to join at the stem as they do, they have to curve around the forefoot.
Now imagine that in a seaway, at speed, your nose goes in hard-ish, but as there's a wave in front of you, one side (we'll say the port side for now) gets the lions share of the wave.
Now, those heavy rails, curved from out near the chine, right round and into the stem, dig in and grip the water and want to follow their lead as best they can, trying to take the bow with them.
As they're low down on the boat, with plenty of 'mass' up above them, the boat will tend to roll 'out' in the motion, or high-side' for you bikers, as it does this, those offending rails are presented deeper, and firmer into the wave, a vicious circle!
Kind'a like catching the outside edge on a ski, before you know it, the ski's, and your legs, have gone from under you, and the high up mass (your body) want's to carry on the way it was going, so you effectively 'roll out', just as I said above.
If this motion is violent enough, and the back end loses grip, the heavy end will eventually wanna overtake the light end, which now has it's well pronounced rails dug firmly in the wave like brakes.
Of course, all this happens in a split second. Ask Steve Salmon
In 1997 on Windermere, I had Tony Donald in the boat with me (donziman on here) for a record run.
I was attempting to show him how the hull of the 26 (with it's 18 degree transom, and megga in-trim) could be quite alarming if the power were applied, whilst fully trimmed in. (see 'glove' thread)
Once we'd finished the first run, and were making our way to the far end ready for the run-up & return run, I demonstrated this by trimming fully in, and opening the throttle fully.
The torque reaction of the prop, lays the boat over on it's port side, digs the rails in (aided by the nose weight of being trimmed in), and the 'process cycle' as described above happens so quickly, that on a flat lake, in a straight line, I get the rubrail wet, and end up facing about 45 degrees to starboard, all in a split second.
I knew it was going to react, that's why I did it, but never for one second though such a violent reaction was possible in flat water.
It genuinly felt like had I continued with the power on, it would have gone over.
It's noteworthy, that the transom angle on that particular model is well beyond that reccomended by Mercruiser, and that we did have 460hp on tap, but the theory is still the same.