Is it possible to sneak out of Konpeki Plaza without triggering the "Intruder Detected" message?

While stealthing the Konpeki Plaza escape (The Heist) I noticed a few different actions will trigger a "Intruder Detected: Enemies have been alerted" message. One example is trying to hijack the camera on the top floor - at least when the Netrunner is still around. It seems like the enemies have a more aware patrol state after that. So with the power of Quicksave I've managed to get through most of the hotel and carefully avoid causing the alert status.

However once I get to Reception, there is an invisible line which triggers the message 100% of the time. It's in front of the desk where the guard is standing in front of a laptop. I shouldn't be close enough to be seen by the camera on the far side of the room, although doing anything to that camera - even turning it off from out of sight - also triggers the message.

Is it part of mission scripting that players get the Intruder Detected message there, or is it somehow avoidable? If it's avoidable, does that actually do anything related to mission rewards or the story scenes that follow? I'm guessing the Delamain taxi would trigger it if nothing else does.

Note that this is slightly different than the message shown when enemies see a knocked out guard.

Solution 1:

It's not possible to avoid that message.

I spent some time testing this, and it turns out the message isn't triggered by an invisible line, but by your line-of-sight with a specific heavy armor guard when he spawns at the far exit of the lobby. Further, it's not him seeing you that triggers the alert - it's you seeing him.
I confirmed this by sneaking backward along the wall all the way to the exit. You can hang out at the bar and admire the architecture as long as you want, then take a leisurely stroll to the elevator, as long as you don't see that guard. As soon as you turn around and see him, it will say "Intruder Detected". Cartoon logic for the win. It must be looking in that direction that spawns him. (like NPCs on the street)

Ultimately, as Kaizerwolf points out in the comments, it is unavoidable due to the story. When the guards in the parking garage say "Where'd that limo come from?" the alert pops up. I'm not sure if the earlier detection was a bug (or just haphazard mission scripting), but it's got to happen either way.