Best way it'd stand up in court is to prove if the floor has deflection, and then see how it was dealt with if it has. If it doesn't have any after lifting all the tiles, chances are, it'd be thermal shock.
Though the pics there show limited adhesive on the tile, the cracks seem to follow suit with the substrate which could suggest deflection perhaps? The tile must have cracked when the floor did. And as you say, the adhesive becomes loose with thermal shock, and although it could crack the tile, I don't think it'd follow the substrate quite so accurately.
Could be the beer talking. :drool5: