OK Mr trained cabin crew Potential. try this scenario.
Your mates runs in and shouts fire - panic ensues and a crush develops at the door as the passengers rush to get away. In the crush 8 people are killed. The subsequent investigation discovers that the cause of the smoke was an overheating fan bearing which had already been shut down as part of the flight deck crew's reaction to the situation. There never was a fire - only smoke.
Who is going to thank your friend then?