The situations you describe.. I would have acted the same and cannot imagine anyone getting offended over it (as per experience from comparable situations). Did you find out why exactly you caused problems and what their feelings were and why? People can be hurt when they are made to feel incompetent or looked down upon, for example. Sometimes they have a bad day. Maybe it was the precious new printer and you put an ugly sticky label on it without asking (some people are like that with 'their' stuff). If you understand what exactly the problem is/was, you're half-way to fixing it and/or doing better next time.

(Note that I'm living in a hippy scientist bubble where you have to work hard to make people take something personal, so I'm playing on the easiest level.. (plus, young woman bonus))