Hans: How was Goyon and Ginsells builders mark explained away?
SC: Can you explain exactly how these marks found outside G1 actually prove (beyond reasonable doubt) that the painted marks allegedly discovered inside G1 must therefore be authentic? How exactly does that work? Or are we just assuming that because some of the signs (what was it Hermione said) - ah yes - are "comparable with" each other then they must all be authentic? Really? How so?