When someone or something has occurred which is bad and cannot be fixed. It can either be late for a person, or a situation can be late
Its late for a person when they find themselves in a problematic situation which they either cannot escape or cannot improve (i.e. getting caught cheating in an exam etc...)
A situation is classified as being 'late' when it is bad, and will almost 100% not have a good outcome (i.e. when you fall down in front of a large group of people)
"Late" situation
Person 1: I saw X got 23% in their exam
Person 2: Ah late
"Late" for a person
Person 1: I got caught cheating in my test
Person 2: Its late for you
Late (slang)