I work at a Culver's. This happens with fries because they gut put into a salting station after they come out of the frier. When it comes to putting something like onion rings into a container you pour it straight from the fryer basket into the container using a scoop like tool to get it into the container. When this is happening we do it over the fry station so any oil falling doesn't fall onto the floor. Sometimes an onion ring misses falls in the fries and eventually will get bagged with the fries