This movie is good character study of how perceptions, past experiences, arrogance, scant proof and emotion can masquerade as reality and lead you to believe and do things that are out of character and result in devastating consequences for all involved. On another level, it tells a story of how "fixing" a bad situation by doing more bad things continues to have a negative impact on lives - living with the guilt is not easy and blocks happiness in life. Finally, it tells a story of how doing a "little thing," an impactful gesture, has the potential to redeem one person and create a more positive life trajectory for someone else who made a terrible mistake.
The negative reviews on this movie are borne out of comparing it to other other movies believed to be in this genre. Take it for what it is, acknowledge the life lessons and you will enjoy it.