Did you guys even considered it was a hacker maybe?
There are reports of people doing this kind of things from time to time. Hacking gets people banned really quickly, so they only get to play a few games before the problem is solved.
On another note, that opening is possible with 2x Cremation, 2x cremation fodder (photons, etc), 2x Phoenix, Lava Golem, Fire Tower (opponent is going second); but OP specifies no Immo was used.