When someone makes a promise they are expected to follow through with it, especially if it is something important like driving someone to the airport
Context: My friend promised me that he would drive me to the airport but he never showed up and I missed my flight.
Hypothesis: My friend never showed up to drive me to the airport and as a result of his irresponsibility, I missed my flight

Given this context, determine if the hypothesis is true (Yes, no, or unknown)?