Ultimately, the buck stops with the individual, and you can't completely outsource personal responsibility.
This advice is pretty bad, and reeks of survivorship bias. This "truthiness" approach to safety purposely ignores the countless cases of morons getting themselves killed by intentionally ignoring directions from emergency services.
Let us admit that they are usually right. But not always. Remember that.
Hard to quickly judge: How much applicable good training/experience does the law officer who is giving you directions (in an emergency) have? And ditto for the command structure behind him, which is most likely where the "direct people to go $This way, not $That way" decisions are coming from.
At what point does someone stop becoming "average people" for us to think that our gut doesn't outsmart them?
Lets not forget that "average people" are commonly barely better than animals in emergency situations. Look at how much training it takes to ensure a building full of people don't trample each other to death in the event of a building emergency.
There's a very wide gulf between being ultimately responsible for your own safety and assuming that your immediate, uneducated gut reactions are more informed than professionals with training.
Let's assume you are right, and just presume that a police officer is as useless in an emergency response scenario as your average Joe.
Police officers are a part of a regional- and state-wide organization dedicated to respond to emergencies, collect and process information from multiple sources including direct presence in critical areas, and coordinate the efforts of all members. All members, including your hypothetical police officer.
Do you really think that your personal ignorance and lack of insight and context and situational awareness is no better than that of the police officer who is integrated in that state-wide organization dedicated to act during these events?
Industrial levels of arrogance and presumption are required to think the average Joe knows best on how to act during an emergency than emergency responders on the ground.
Trust training, not your gut.
Blindly following orders makes sense if 1) you are an idiot or 2) your gut agrees and it seems sensible.
If you are knowledgeable and you think something is wrong, that should be cause for second-guessing.
The problem is that every single one of us is an idiot at <many subjects>, and in a large number of them, we don't even know that we are idiots.
If your town is on fire in a sign, possibly outdated, points You Into The Inferno, don't follow it!
If there is a safe spot that you have personal knowledge of, go there despite the directions.