Well the video dosn't show how powerfull the bow is... (in fact it gives no information on any variables)
I found a poster on the webside and it seem to be a 25lb bow.... the arrow is also very big and bulky (thus not for penetration).
The poster have a 60lb bow penetrating 60mm at 25feet and above 30mm at 50feet (for the 11 layer authentic patch, I assume they still use with the bulky arrow).
They alwso have pictures of (clearly) untrained people 'hitting' the armour with various objects (presumably weapons) on their
homepage.
For a experimental archaeologist trial this is really horrible.... Its like something from the 1970'ies.