I’ve seen multiple new users drag Macintosh HD or Documents to Trash in literally the first minute of using a computer. It was perhaps the most common first action I witnessed. Fortunately, none of them located the “Empty Trash” command before I stepped in.
It never crashed the system, but this was in the 90s when we were already on System 7 or even OS 8, so I’m not sure how the older versions handled it. Dragging a disk icon to the Trash on the classic Mac OS ejected the disk, so I wouldn’t be surprised. Simply dragging the System Folder shouldn’t cause an instant crash, but it would fail to boot if you restarted for sure. So the story could be mostly accurate but just missing a step.