ABC 7 screenshot by Chris Matyszczyk/CNET

We're always being told -- and quite rightly -- not to have easily guessable passcodes.

Once in a while, though, making it easy to get inside your head can help save a life.

Melissa Vasquez, 28, was involved in a car crash somewhere near San Jose, Calif. Police say the OnStar alert system in her Chevy Cruze sent signals, but that the locations given revealed nothing.

The accident happened some time on Monday. By 3 a.m. Tuesday, Vasquez's stepmother contacted the police. She was lucky that in the Campbell police department there is Officer David Cameron.

A self-described geek, he had an inkling that wherever Vasquez was, her iPhone would be with her. So, as ABC 7 reports, he went to her house and found her iPad. Surely, he thought, he'd have a chance of finding her through the Find My iPhone app.

But how to get into her iPad? It was passcode protected.

He told ABC 7: "I made an educated guess based on a series of common numbers people use for passwords and on the third attempt I was able to get in."

There will be those slapping their foreheads that a passcode could be so simply worked out. But Cameron's human and tech education meant that, in a mere 20 minutes, a rescue helicopter was dispatched to the location given by the Find My iPhone app.

Vasquez was found, alive, lying at the bottom of a 500-foot ravine. She had been thrown from her car.

One piece of technology may have let Vasquez down, though. An OnStar spokesman told me: "Our subscribers' safety and security is OnStar's utmost concern. We are currently conducting a complete investigation, including information we have received from our call centers, our cellular network provider, our engineering team and the local authorities to better understand what occurred. OnStar carries out more than 4,000 Automatic Crash Responses each month and each unique case requires a coordinated effort among a team of first responders. We will continue strive for excellence in our role and give praise to the officer who went above and beyond to reach a positive ending for this situation."

By contrast, one police officer's quick tech thinking -- and an app that, thankfully, worked -- may have saved Vasquez's life.

Updated at 7:37 a.m. October 16 with comment from OnStar.