From what I'm hearing a certain competitor to betsofbitco.in didn't have any problems in determining a clear outcome to the same bet...
Not the same bet. betsofbitco.in allowed for +/- 25% on hashrate (which was met), but the competitior's bet only allowed +/- 10% (which was not met).
Same clear outcome.
A dev board is not a device as defined by the bet.