Ah, I love the books. Dreikurs made a career out of interviewing kids and training teachers, so I feel like I experience a lifetime of wisdom while reading his books. That said there is no substitute for thinking on your feet.
It's the thinking on your feet part that get's you in hot water as a parent. Especially when the timing is bad, your already exhausted and stressed out and should still act as the "adult".
As you said, saying you're sorry helps a lot. Not having it happen to often as well. And as long as it's not abusive (as subjective as that might be) it is, to some maybe cruel extend, part of training for life. It's also borderline bad parenting. Usually I care a lot more about results and effects then intent, when it comes to parenting and relationships in general intent plays a huge role so.