Hey so ive made up that there is a security technology event.

This would be an event where companies etc. Show there technologies to potential investors in the corporate sector.

This is where the protagonist 'a mechanic' is minding a droid he helped design.

Here he meets a girl, who helps him with an audio recorder he was confused about.

Anyway then I just need one of the technologies there to cause some catastrophy causing a small evacuation. This is where I am stuck

I was thinking could either be:

1. Someone trying to sabotage the corporate security industry (either some competitor or criminal)

2. The creator was some kind of outlaw tech, and it had some great flaw only now apparent.

3. Some type of sith technology which no one understands maybe developed after some archaelogical find.

This makes it so the character doesn't finish talking with the girl and has to follow clues to find her.

It is all dependent on what kind of interaction you would like your players to have. I spiced a whole idea from the three you had-

A race against a freelancer slicer inside the system, which uses the utility systems to sabotage the event and create chaos, while his minions (system virus, droids, minion slicers) use sith alchemy-infused gadgets to hijacks various prototypes from the event. Intended to be solid to competitors.

Player needs to overcome the environmental set pieces, minions around the complex, and the finale cyber battle in the system against the slicer. Spice it with your own story about His droid and the girl he needs to find, and the other event participants, who may (which is hindrance) or may not (needed to be convinced to help) meddle with action.

Tech events are disasters waiting to happen in general. A security-oriented event even more so. Convention venues are usually large enclosed spaces, so something as simple as a small fire would involve a general evacuation. Some possible causes warranting temporary evacuation:

• The aerial pest-control droid made to eliminate (with blasters) small annoying flying creatures... like the hovering camouflaged camera droids four booths down.
  
• The portable force field controller that unfortunately sometimes causes energy arcs to other power sources that are placed too close (like every booth surrounding it).
  
• The slicing kit that can "instantly delete your sensitive information wherever it finds it." But accidentally deletes everything in a 50m radius from its booth... including the forbidden targets list in the large sized security droid across the aisle which immediately opens fire on previously forbidden targets, like people, tables, chairs, lights, power connections, beverage cups...

Do some research on what happens at “Black Hat” and “DefCon” conventions here in the US.

Fake ATMs that skim everyone’s card details?

Fake cell towers that record every single conversation that occurs?

Fake wifi base stations that record every bit and byte of traffic?

Zero-day security vulnerabilities being exploited during the conference, using auto-hacking tools like Metasploit?

Password cracking tools like John-the-Ripper and l0ftcrack being used on every connection that is captured, and then publicly posted in a central location as soon as they are found? Must include picture of victim, name and home address, social security number, and all other personal details that were found.

Custom badge kits being made so that attendees can hack together all sorts of cool stuff?

Now, what does the hotel and convention center have to do to prepare themselves for such conferences?