Fair enough. In this case you system should be treated as hostile when you come back into the office. It doesn't have to effect you even in the office, it just means the network you are on should be quarantined from anything that may be sensitive.
Networks should be like that anyways. I only have access to data I need.
Also it sounds like your role is IT focussed to at least a degree. If you are on site making your employers software work on other peoples system you must be operating in a role of some IT trust. This is not the same requirements as for people who have no idea how computers really work.
That's fine, but, ultimately, I'm an end user. I am not in an IT division that manages our network, infrastructure, procurement, etc. I am in a revenue generating customer facing division and I get issued technology from the IT division. Blanket rules being discussed way up the list by ACs that "Users shouldn't install software" are plain wrong. I'm a user.
Karl's version of Parkinson's Law: Work expands to exceed the time alloted it.