Morning,
I'll try and clarify the purpose of kicking the door.
The door is shut and locked, however the door swinging inwards or outwards has no relevance to this.
The kick is made to the fourth panel to the right, and is aimed at the panel in an attempt to break it, the same way as the cricket bat would be used.
Panels do not have an interest or particular strength depending on which way the door opens. The strongest part of the door is the frame (outer section) and the weakest the panels (inner sections).
If you thought you could bust the door open you would the kick the frame of the door on the right, and yes, it would be very difficult to achieve as the door opens the opposite way.
I hope this helps to explain the reason why it would be perfectly logical to kick the door panel from the outside of the toilet.