I just watched an episode and Richard replumbed a sink and disposer. There were three traps, one for the sink, one for the disposer/sink and one for the dishwasher. He remarked that he had never seen three traps before. He replumbed it to solve the owners problem of water standing just below the sink basket by combining everything into a single trap and also connected the dishwasher discharge into the disposer. Granted there is a provision for that connection HOWEVER you better check with your local plumbing codes. It may not be correct. For example in Chicago and the State of Illinois it states: Illinois Plumbing Code Sec 890.710 Food Waste Disposal Units .......Dishwashers shall not discharge into food waste disposal units. and again in Sec 890.770 Dishwashing Machines .... "Dishwashing machines shall discharge separately into a trap or tail piece of the kitchen sink and shall not connect to the food waste disposal unit.
No the poice aren't going to come and write you a citation but if you sell your home and your buyer has a home inspection, it will probably be an issue you'll have to repair.
Check your codes prior DIY repair.