Hi Malcolm,
If any damage or sticker/object larger than 10mm in the wiper sweep directly in front on the steering wheel (290mm wide) then its a fail, all other damage/objects (except parking stickers) larger than 40mm in the rest of the swept zone should produce a failure.
Tester should have failed it for the dangly tree, but maybe thought as he has already failed he didn't need to (more typing !)
If the satnav was mounted inside the swet area that should have failed as well.

Regards
Dave