Basically if you try to hook someone there’s a chance that the hook hits them, makes the ‘connected’ sound, then breaks off similarly to how it would if something obstructed your view midway. Taking a highlight shows the hook missing the target instead.
This is a link to a recent Reddit post containing examples taken from streams.
https://www.red----dit.com/r/Overwatch/comments/99fn4l/roadhogs_hook_has_been_broken_since_three_patches/
Here are two examples from the post:
https://clips.twi----tch.tv//ConcernedWealthyMinkBabyRage
https://clips.twi----tch.tv//ColdAveragePandaSaltBae
Small compilation of the bug found on Youtube:
https://www.you—tube.com/watch?v=8Qqz_XuoeBs