The 1p bet was a supplement to the 10p bet and not an independent wager so for me the claim of it being 1900x + bet is invalidOK I've just recreated this myself to understand what happened. (I've never played the game before.)
The 1p 'spin' is clearly not an independent spin, it has to be linked to at least one previous 10p spin, it is impossible to make a 1p 'spin' on this game without first making a 10p spin, and depending on how the reels end up you may need to do multiple 10p spins to get the correct reel setup to allow the 1p respins.
The triggering stake for the spin is 10p, I don't even think that's a matter of opinion, so much a matter of fact. The 1p 'spin' is a modified result of a linked 10p spin that leaves the reels in an unfavourable state.
All I'll say is thank you very much to Maja for running for the competition, it's a shame that the 'winner' saw fit to show such discourtesy to other CM members and very clearly try to bend the rules as far as possible to sneak a winning entry in at the last moment.