Penny did no different than when an airline passenger has to restrain an unruly threatening passenger on a plane until they land. You hear about it all the time.
You are correct.
But unless an unruly airplane passenger dies, it’s not manslaughter.
We are either the party of laws or not.
If someone dies while being restrained on an airplane, it’s manslaughter.
Also, who restrained the unruly passenger? Are they authorized? Did they act without permission from the crew?
Many factors.