The movie slide-strip is silly, if you look at a still image of the scene, the disassembly lever is already down.
Besides, with any semiautomatic, anyone close enough to disassemble your slide can push the slide far enough out of battery to stop the gun from working.
The simplest solution? If someone lunges for your pistol, shoot them.
The 92-series is a wonderful pistol with some legitimate criticisms, most notably the long first trigger pull and the weight/size. The risk of being "field-stripped" is, in my opinion, not a legitimate criticism of the design.
That said, if you're going to have to conceal, the reduced weight of the also-excellent G17 might be nice.
13 Pistols, 5 Rifles, 1 Shotgun, no time to shoot them