If you don't mind the first layer disengaging from the bed after it cools, it's okay to turn the heated bed off. Unfortunately, if the first layer disengages, the rest of the model will follow.

When printing on a heated bed, the first step to getting the model free is to let the bed cool. If it cools during the print, you'll have a mess on all the layers after the model starts to slip and slide. Jams and broken parts could also result, depending on the severity of the mess created. The latter is unlikely but not impossible. Another possibility, much more likely is that the extruder nozzle will accumulate a huge blob of filament that is very difficult to remove and CAN result in broken parts.