Its hard to shove a 4-wheel diesel without getting bad interplay in the couplers. It might be good to block and limit the movement of any coupler coupled to that diesel.
We all know of the common GP-9 that have extended swing couplers for tight switching, that can not be moved or towed without coupler blocks to restrict that swing.
If the Loop diesel slips a moment when pulling the #9, it ends up being shoved and that is how it end up on the ground by my understanding. But I'm not there so if you have data, fire away.