Custom Freight Car Sorting

That's some incredibly well planned automation for Plarail. Stop/gos and 3 way points are fairly simple to motorise, but it looks like they (somehow) modified a stop/go to act as a decoupler. From what I could see, they didn't replace any of the couplings with magnetic ones and the trucks clearly don't "sway" while being pushed, meaning they weren't simply uncoupled beforehand. I have no idea how they made a decoupler for hook and loop couplings, especially given how strong Plarail ones tend to be. Hopefully someone here might have a mechanically plausible theory.