Hey Shadowspawn here, one of the guys who killed you....
There have been a lot of pro tips in here, but here is what actually happened....
You discovered the asteroid, and we hauled our asses towards the first scan point. Around the 4th scan, we spotted, and engaged you. That's why it felt so short.
My tip for you, freshly discovered asteroids have a clock, probably. The asteroids that have already been broadcast might be a bigger gamble for ore, but you're less likely you see someone there....less likely.
Glad you made it out in pvp space! Hope that gives you some insights! See you out there
Shadow