People have brought small pets on planes before, got loose and no biggie. Once a scorpion was found on board but the plane still continued to its destination. The passenger would have been told to do not open the box, period.
That may be, but...
People have brought small pets onboard before, those small pets have gotten loose, and it entailed many thousands of dollars in damages. (In one case, the airline claimed that it had no choice but to ground the aircraft in question, because it could not be completely ruled out that the rodent might gnaw on some vital electrical cables. Not saying that I agree / disagree - but it happened.)
The passenger would have been told to do not open the box, period.
Yes, and the ditsy passenger would gotten anxious and suffered a panic attack and would have gone and let it out anyway.
Regards,