So I finished the rest of the series, and I did rewatch the assassination scene.
Like Korean dramas that have similar set-ups, Bodyguard is a drama written for a woman. I am not sure how a man could enjoy watching this, especially with all of the SJW messaging thrown in -- minorities in every scene, women in authority, and so on. I'm surprised there was actually little LGQBTXYZ messaging in this one. Maybe in the next series. As for the mystery part of the procedural, it actually isn't bad for a contemporary BBC production but you'd have to sit through all of the SJW noise to appreciate it.