I don't think so. Maryland isn't the most restrictive state when it comes to firearm policy[1], but it's a long distance from "no gun control." I'm also not certain that the chance of armed encounters is terribly high in Bethesda, though I'm uncertain if those crime statistics are recorded or what terms I should use to search for them. To give a comparison, the homicide rate per capita (which I suspect would correlate to some extent with police interaction with armed individuals) in Montgomery County (where Bethesda is) was 1.4/100,000 in 2016 [2]. For Australia at large, the rate is 1.0/100,000 [3], so pretty comparable. These police officers don't seem to operate in an area that is notably more dangerous/violent than Australia.
I do, however, think the issue is cultural. Many police officers in the US seem to perceive that they are in danger 24/7, and this effects how they interact with people on a daily basis. There is a preference for an overwhelming show of force even when it's absolutely uncalled for. This probably contributes to a feedback loop that causes the general population and the police to trust each other less and be more confrontational. And I don't seem to be alone in identifying this as a problem; if you search for problems with police culture in the US, you will find a large body of criticism for the default behavior of police officers.
[1] https://en.wikipedia.org/wiki/Gun_laws_in_Maryland
[2] https://www.montgomerycountymd.gov/POL/Resources/Files/MCPD%... (Page 4)