It seems like there's a bug if you drag your mouse from the board area, off the board, then back on; it will automatically select the first unclaimed tile the cursor hits. I just progressed the game to a 14-36 loss by just waving my mouse randomly without a single click.

It seems to require some fairly fast movement, but I did accidentally trigger it a few times when I was trying to play for real.

I've tested on Firefox 89 and Chrome 91.