It's possible the crow inhaled water while trying to get out of the pool. Or it's possibly affected with West Nile Virus and chances are it may not make it. Is there a vet you could bring it to, or nearby wildlife rehabilitaters? I'd put the bird in a box or cat carrier to keep it safe from nightime preditors and bring the bird to a rehabber ASAP. Covering the crow will keep it calmer too. Keep us posted....and hope the poor bird will be OK!