There was no realistic scenario in which this would cost your friend more than the plans they made for the next day!
Do note that, although they probably weren’t in this case, the consequences of dropping your plans for the next day can be almost arbitrarily bad.
For example, it might cause you to lose your job, which in turn causes you to lose your health insurance and your flat.
(In another situation, you might be told “either you work tomorrow or you’re fired”, and someone could tell you that you’re not in danger of losing more than your plans for tomorrow. But in that situation, maybe your plans for tomorrow include “visiting the doctor to get the insulin you need to remain alive”.)
Do note that, although they probably weren’t in this case, the consequences of dropping your plans for the next day can be almost arbitrarily bad.
For example, it might cause you to lose your job, which in turn causes you to lose your health insurance and your flat.
(In another situation, you might be told “either you work tomorrow or you’re fired”, and someone could tell you that you’re not in danger of losing more than your plans for tomorrow. But in that situation, maybe your plans for tomorrow include “visiting the doctor to get the insulin you need to remain alive”.)