Everyone knows this? Really?
Maybe she was just a complete nutjob who forgot to take her meds that day and decided to wear her bomb outside her hoodie.
The police did the right thing.
In other stories airport personnel actually left the building because she didn't respond to questions about what was on her hoodie.
In other words, she did it on purpose
Maybe you need to explain the purpose of the flashing LEDs in a bomb. You can't because they don't have a purpose, which is why no one besides holywood builds bombs with flashing LEDs.