I used to burn about 4000 gallons of "heating oil" (offroad diesel) in my equipment every year, and the real issue is whether it's kerosene heating oil or red died. A mix of either should be fine, but I would hesitate to run kerosene regularly due to the lack of lubricity. I'd be pretty bent if my red diesel was contaminated. Course, there's also FARM diesel. You get followed by a cloud of acid rain running THAT stuff, and you have to change your oil more frequently to make up for the ph change of your oil.
In short, you got nothing to worry about unless it is non dyed kerosene, and your tank was empty, or the 'man catches you shirking road tax.