Got it — well, just to focus on those two examples —
For the house one, in order for the answer you brought up to be required, we’d have to assume that these other ways of getting into and out of the house are ones that one could “break in” through — we don’t have the information to make that assumption.
For the coffee one, the excess is important — to understand why, imagine this analogous argument:
“My wife says I overeat, but that’s not true. I eat about 1000 calories for dinner, and this is not an excessive amount to eat for dinner.”
In order for this argument to be valid, it doesn’t have to be true that I don’t eat at any other part of the day. And that’s the equivalent of not having any other substances that contain caffeine.
The point to take away isn’t to avoid answers that fill that gap, but rather to do your best to focus singularly on evaluating as best you can whether an answer is truly required for the argument or not, without biasing yourself with considerations of degree/significance —
HTH — MK