At the beginning when the turtles are on the roof & Donatello spots Dogpound & Fishface he says " I got eyes on one giant dog & fish, 6 o'clock". Donatello is using clock position to tell the turtles the direction of the bad guys. He means to say 12 o'clock meaning that the bad guys are straight ahead not 6 o'clock which really means the bad guys are behind them.