Well I'm not much concerned with the woman "being worried" given she was drunk driving.
Otherwise, that's an incredibly stupid thing to say, though not surprising. The police feel every bit as under attack as anyone, and one needs only look at any trending story that involves cops on social media to see people expressing unabashed hatred towards the police.
Meanwhile, they're out there every day working one of the highest-stress and most dangerous jobs in a country where any person they approach may be carrying a gun; the many thousands of interactions a day that go well will not be reported, but every time some racist or sadist does something terrible it will be plastered across the internet, with many people coming to view this as being representative of the police force at large.
I have a few relatives that were cops for a time, and they're endlessly stressed about the situation despite not being involved anymore. It's a job that, when done right, is still hugely stressful and risky; when things go wrong, it's potentially deadly. When I think about being asked to confront a dozen or so people a day that either are doing something illegal or appear to be, fully knowing the odds of them carrying a gun are quite high, I can understand how the job not only begins to manifest symptoms akin to PTSD in many officers, but can also engender hostility, hatred, and (in some cases) even racism towards those they're confronting every day.
I got a bit wordy there, but as I love my relatives who were cops and know them to be good people I feel an obligation to offer some defense for them. This guy here said something incredibly stupid out of frustration, but I really think he might need to be fired even if it was a morbid joke to a drunk moron in a car, and at the very least must face a lengthy suspension; when you're in a position of authority you are morally obligated to be the more patient party in any encounter, and you need to know that many actions and words are off-limits to you as you hold real-world power over the people around you.
I don't have any solution for this issue (outside of decriminalizing a number of things and ending the War on Drugs, which seems unlikely)... While social media is great and useful in exposing injustices such as the systematic racism in our policing and such, we as a people have shown ourselves far too immature to make use of this information responsibly. More than anything, social media engenders animosity, hatred, and blanket generalizations, which then leads the attacked party (in this instance the police) to get defensive rather than looking to correct such issues as they would in a calmer environment.
There is one thing that I think would help a good deal, though: the police need a lot more mandatory, paid vacations. It's absurd to treat policing as if it were some conventional job, and these people truly require far more time to rest their minds and get away from the overwhelming stress and anxiety of their daily jobs which, in many ways, requires a combatant's mentality. As things currently stand, we have a police force full of overwhelmed members who are often unknowingly falling victim to their own anxieties and trauma when interacting with others.