Evacuation philsophy has kind of evolved in recent years to be a little more deliberate in making the call, since you're pretty much assured of a few minor injuries from the slides.

But active fire of almost any sort, unless maybe contained in a BCB, is still all the justification you need.

In the cockpit you're relying on info from outside sources (unless there's obvious, significant fire/smoke in the cockpit/cabin, then it's time to go). Ideally you're talking to CFR, who know what they're talking about, but in this case it looked like the info was probably coming from rampers via ops.

Very good odds that I'd have evacuated in that context.

Keep in mind, many fire fatalities are caused by smoke, not fire. And pax and crew inhaling nasty smoke from burning composites, fluids, etc is going to have health ramifications at least once they talk to a lawyer.