Because young girls never exaggerate or over-dramatize.
I couldn’t find any details about the case just that the father gave the miscreant some money and then within some short period of time the man was trying to get into a BR stall with the girl in it and then within some other period of time the dad beat the man to death, during the day, with lots of people in and out of that shop, presumably with cameras in the store and outside. The story doesn’t say what the girl said or didn’t say. Too bad they didn’t go with a jury trial but why was the judge so harsh given the event? What came out in the trial that would have biased the judge against the father?
If the story about the girl is true then the prison sentence comes across as unusually harsh against the dad and I would hope he could get a pardon or a commutation of sentence.
Does that answer any of your concerns?