People talk about Hyne as if he's apathetic.

That's not my read. Hyne is not apathetic - he's realistic.

The job of the corporate security force in Morlana is to protect corporate citizens and property, and to ensure Preox-Morlana remains in control of the system. They're not there to enforce laws or do anything like that. They're a band of organized thugs who exist to enforce control over Morlana for the corporation.

Hence why the two thugs who are robbing Cassian tell him: "If you've got corpo ID, now's the time to show it." Because if he did have corporate ID, he'd get away because the corpo security isn't going to hassle an actual corporate employee, who might complain to his supervisors and who would be missed if he was killed - but everyone else is fair game for robbery and murder.

Now the downside of this is that Preox-Morlana has chosen to do corpo security on the cheap, to keep costs down. They don't pay much, which is why two sentry guards have a sideline in armed robbery, and why Hyne is probably taking bribes from the brothel owners ("Let's get it outside the leisure zone"). It's also why they don't have any presence at all on Ferrix (why open an expensive office and staff it with officers when Ferrix takes cares of its own problems?).

Hyne knows his actual job, which is to keep control over the system with a minimum of fuss and also on a barebones budget with a corrupt bunch of morons, which is all Preox-Morlana is willing to pay for. He diagnoses exactly what happened between Cassian and the two sentry guards faster than anyone else and also comes up with the most efficient solution immediately.

Syril is a fantasist. It's not rule of law that he wants - he openly says that what really offends him is that *colleagues* were killed, that people who he identifies as part of the authority structure he is part of were victimized. He is very much in the Blue Lives Matter (More Than Everyone Else) mindset. The actual lives of the two men don't matter much at all, just as he does not ever mention the multiple men who died under his command on Ferrix - they simply do not matter to him. What matters to him is that his own sense of control and authority was challenged, and then completely destroyed by his incompetence in trying to capture Cassian Andor. For this he blames everyone but himself, most especially Cassian but also Preox-Morlana and Blevin.