One thing that doesn't factor into this argument is the professional nature of the hit — how he managed the gun, the silencer, the messages on the bullets, the getaway, and the precise reconnaissance that allowed him to know exactly where his target would be at that exact moment.
That doesn't align with the characteristics of a typical personal vendetta.
At the rate insurance companies hurt people, it's likely they've hurt professional assassins, special forces people, etc. It doesn't have to be a hired hit to be professional in execution.
I knew a person who went on a personal vendetta against his old boss. The set up he did was very elaborate, including making it look like he went on a hiking trip the weekend he murdered the ex-boss. Unfortunately for him he was a prime suspect because their well-known beef.
Don't underestimate the amount of thought someone truly resentful will put to this kind of action.
The video shows the gun malfunctioning repeatedly and the shooter having to clear those malfunctions by racking the slide. That's likely caused by a poorly-installed silencer. Hardly professional.
That doesn't align with the characteristics of a typical personal vendetta.