Heya Odd,
I'm still having trouble justifying this part of her backstory.
Sera began to deliberately give out minor bits of misinformation to other knights working on the same cases as her to slow them down so that she could get the credit, but was reported to her superiors. No condemning evidence was found linking Sera to this crime, meaning she could not be formally punished, but it was clear to everyone from the way that she acted that Sera was guilty.
Maybe it'd be best to leave out any mention of wrong-doing, and maybe she just got demoted for underperforming?
The thing about this is, any ranking Inquisitor would be able to find out that she wasn't telling the truth, and if they got a whiff of what she had done, they would be able to find out. How is that, you might wonder. Let me direct your attention to the Inquisitor Rewards from the Lightning Knight Write-up:
Inquisitors: Whisperwill - The Whisperwill comes in the form of a large silver and amethyst ring that is worn on the thumb. It will glow very faintly when you are standing in the presence of someone who is intentionally and specifically trying to decieve you. This tool is invaluable when suspects are being questioned. The Whisperwill can be confused at times if the individual does not does not truly understand that they are lying, in these cases the ring can give false readings.
Inquisitors - Memory Playback Crystal: Sometimes, it helps an Inquistor to be able to view things as they happened, rather than simply relying on stressed memories. These crystals were made to fill that exact niche, allowing whoever is holding them to draw themselves and the people around them into a memory. These memories can be repeated at will, allowing the Inquisitor to gain evidence that might otherwise be forgotten or lost, though the memory has to be played willingly.
So you see, even a somewhat intermediate Inquisitor would be able to find out about what she'd done, and she would likely get thrown in jail or out of the LK at the very least.