Someone I'm subscribed to on YouTube filmed a video of his friend and him just testing some HID lamps (and a fluorescent lamp starter) on an NST. Fun stuff.

https://www.youtube.com/watch?v=5Mrl-DX2WWo

"Buzzz-zzzz-zzzz!"-Angry magnetic ballasts.
Also, "you can run the HPS bulb on it, it's a standard magnetic ballast" is one of the cringeworthy statements here, lolol.

Yeah, they obviously don't know all the ins and outs of discharge lighting. They're not lighting enthusiasts, so who can blame them? 

And I noticed that the 50hz hum sounds different than the 60hz hum. I talked with a British lg member and they prefer the 60hz hums.
And lol at the fluorescent tube that took too long to start.

I like the 60hz buzzing more. Also, I found it really funny that "How to train your dragon" was playing in the backround (don't ask me why  )

NST and HPS lamp-big mismatch there-the NST started the lamp-but will not run it right because of the voltage and current of the NST-yes,the NST is a "ballast"of sorts-for a long,gas filled cold cathode tube.Neon sign suppliers sell a NST tester-it measures the SC current of the transformer-it won't hurt the NST to short it-remember it is a current limiter transformer!The sec current is what is marked on the transformers nameplate,as well as the no load voltage.

I'm sure they knew that - they just wanted to see it light up.