Whilst the authorities make every effort to scan items coming in or leaving for overseas, they simply cannot cope with the sheer volume of luggage and items. I would imagine that unaccompanied and postal items would get more attention than little old ladies with who knows what else in her bag. Of course they won’t tell you that.
What we often fail to recognise is just how much of a struggle to survival it is in the natural world. For example, spotteds can live for 20 years in the wild and have an average clutch size of 10 or so eggs. If a female produced 60 eggs in her lifetime and say 50 hatched, that would not be abnormal. Yet only two of those offspring need to survive to maintain a stable population size. That means 96% of offspring will perish - by predators, starvation, dehydration, disease, injuries and so on. I reckon a comfortable, low risk zoo environment would not be an undesirable alternative by comparison.