It had fluid because there were no overheating messages, either the unit failed or most likely fasteners we're NOT torqued down to specs, a lot of mechanic use an impact gun to tighten things up and do t care about properly torquing bolts down from which bolts become loose or snap. With Mercedes we have to replace most of the bolts and torque them down so catastrophic situation don't happen. I just got another loaner car and they promised me my complete cat will be fix, and if it's a Subaru issue, Subaru will take full responsibility too.
1920 prohibition style been on the list for a while 😉 I have not try it yet
Thats some hackjob skipping a torque wrench on something that critical. I'd be leery of that dealer going forward