
The major concern is that of leaking water causing damage. Often there needs to be water supply and takeaway lines running behind cabinets in your kitchen, and a leak there could go unnoticed for a long time, causing serious damage.
There is also a possibility that you will cause issues with the drainage of your sink if the drainage from the dishwasher is connected improperly. This could be annoying, but it could also lead to water backing up in areas where it can do damage.