the point of searching a suspect for weapons is to make sure they don't have hidden weapons, not to make sure they don't have evident ones.
Here is something I read once about Vikings, from The Saga of the Jomsvikings: some defeated warriors are awaiting their execution, and one tells the other that, if there is life after death, he will hold up the blade of the knife he is holding after his head has been cut off. The saga reads "Torkel hewed, the head flew off, and the knife dropped."
What's interesting about it to me is not just it's indication of a Viking interest in the experimental method. It also shows that these Viking prisoners, awaiting execution, had access to knives.
Maybe the Taxiwanians are polite enough that they don't search everyone who comes under their control, even if they are trying them for attempted breaking and entering.
Wasnt the character a psion that could more or less jedi mind trick er captures into thinking she was disarmed? Which, of course, leads to why was tossing a gernade on a spaceship/station the best method of escape?
The character has psionic training: Clairvoyance to a level where she can get flashes of significant events; Awareness to a level where she can suspend animation; and a Special talent that lets her cloak herself (it's more like bending the light than Jedi mind tricks).
She used her cloaking to help her pull out the grenade and pull the pin without that being noticed.