As you have learned,
@CMDR SleepyDelegate, there's a benefit to combat in high security and medium security systems. In a high-security system, help will show up almost instantly in the majority of cases. If you can hold your own for a while, combat in medium-security systems will also include help from local security forces- after a longer delay.
Others have hinted at this too: in the tangle of these episodes, it's almost inevitable that you'll inadvertently land a shot on one of the security forces' ships, resulting in a paltry fine and a bounty on you. The fine is almost silly (100cr or 200cr), but the bounty can be problematic. If you go to a station in-system, you'll very likely* be carted off to a prison colony somewhere far away. Instead, I suggest that you take a little detour. Jump to another system (close by) to "get out of dodge" and then take a moment to find the nearest "interstellar factor" where you can pay the fine and wipe the bounty. Use Inara, Eddb, etc. to find this facility.
The first couple of times that this happened to me, I had to get back where I was so I used the return trip get some exploration data that earned me some credits. Make the best of it...
I hope this is helpful. Have fun!
* faction considerations apply here, but the likelihood is high.