Another common issue with inexperienced and younger goalies as they want to use a T push on short distance movements, when a shuffle would have bee the correct technique.
You can see the puck going through the 5 hole, the goalie has no possible recourse because the lead skate has weight on it and is in the T position.
A simple drop from the stance into the butterfly or even a short lateral movement, beginning with a shuffle push, would have allowed him to remain square and drop into a proper BF