Interesting question!
I keep wondering why a terrorist (if that’s what it was) would choose this route, or city of origin or destination? I thought maybe KL is know for lax security, for instance - but your question raises other possibilities.
When I flew into KL, I found the airport fascinating. The ENTRY experience was glorious and beautiful. Well-though out.
The exit experience was somewhere between LaGuardia and Mumbai.
they paid a lot more attention to greeting you well, than sending you off well.