most birds come from Minnesota and if you go to the plants that kill birds and rap birds you will see they spray every bird with something that glows if the bird is bad. they cut the bad part off.(why there are one lagged ones) but what they spray on it is still there. so yes you have to wash all birds if only to get this stuff off, yes it will not kill you but who wants to eat it.
there may be trasses of the bad part of the bird still there so wash to get any of this off also. being it takes 3 days to get bird ready washing is also a good thing.
as fare as i know all cooks clean after cleaning a bird so all is good for this and anyone that does not clean up after washing a bird should get sick. anyone that cleans a bird and all the kitchen needs cleaning needs to stop cooking.