Failed???

Bandit: They were late home last night!
Dylan: But they said they had had a fine evening, great food and company.
Bandit: So what was he in a state about this morning?
Dylan: Well, he was driving so he only had three bottles of that zero alcohol Spanish lager.
Bandit: So?
Dylan: When  he got up this morning, he was feeling a bit whoozy, so for a laugh, he thought he would test his alcohol level on that breathalyser thing he bought.
Bandit: And?
Dylan: It said he was just under the limit!
Bandit: So, if he had been stopped last night
Dylan: And if he had failed the test
Bandit: And if he had been locked up
Dylan: Who would have fed us and put our heater on?
Bandit: Worrying, isn't it!!!!!