So been using the plugin now for a good year. No issues. Until today one guy claimed he called the heli as usual and this happened:

https://youtu.be/AQI6c4mGwpM?t=441

Was this a hack or a bug? Haven't been able to reproduce it.

Post your config is always a good start, Personally I only let admin(s) spawn helis,
But in any case check this line
"Spawning - Max active helicopters": 1,

I did have it at -1. 
My vips can use it once every 24h. So still no clue how this happened.