I didn't expect to see something so violent! The timelapse videos shows in 10 seconds what in reality took nearly 12 hours. Maybe the speed at which it plays back is what makes it feel so violent?
It would be great to develop a system that allows for real time viewing, but that will have to wait.
Not sure what type of slug was eaten, the predator in this case appears to be some sort of Beetle Larvae? You can also make out the worm in the first few seconds of video, the view of which is quickly obscured as the Beetle Larvae makes its way in.