When the city's water supply is shut off the fountain of city hall can be seen going off as well. This would not happen as fountains are not dependent on water mains for operation.
The microbes shown under the microscope are paramecium and not cryptosporidium (probably for dramatic effect).
When the first person (the old lady) flat-lines they don't apply the defibrillator paddles to her skin like you're supposed to, but instead just place them over the clothing/bedding. That WON'T WORK, as defibrillators MUST be in contact with a conductive surface (like skin) in order to transmit the charge.
When Susan pulls up in the drive after picking the kids up, as the girl opens the truck door a crew-member and a reflector screen are reflected in the door.