Although the planet has three suns, all objects only have a single shadow.
The Doctor scans the planet and says it has no lifeforms besides the flesh eating microbes, but it clearly has flora in the form of grass, shrubbery and trees.
The Doctor gives Graham a pair of sunglasses that she claimed was an old pair of hers, yet she had landed on Earth with empty pockets and no TARDIS.
If all water on the planet were filled with flesh eating microbes, those microbes would exist in the wet sand of the beach going up for hundreds of feet, making it unsafe to walk on; yet everyone walks on it unaffected.