Is there a technical reason that makes use of a tumbler legally safe? My concern would be that putting in a clean bitcoin would result in me getting a fraction

Is there a technical reason that makes use of a tumbler legally safe? My concern would be that putting in a clean bitcoin would result in me getting a fraction of a stolen bitcoin and I would be receiving stolen property. The fact that they are fully traceable means that it would be easy for someone innocent to be caught up in something like that.