That’s how you learn
Fathers have a different approach to kids than mothers; while mothers tend to be more protective (some people would even say over-protective), fathers are more allowing and forgiving. They trust their children to learn things by themselves and allow them to spread their wings.
While we appreciate this girl for trying, obviously she wasn’t prepared to drink from this big bottle without any help, and the father realized it a few seconds too late. That’s how kids are – if you take your eyes off them for even a minute, you never know what’s going to happen. Hopefully, this dad learned from his mistake.