A nurse only 3 months and allready trouble?

So, I get called into my DON's office the other day.. she wants to ask me some questions. She saw the immediate worry on my face and states "Oh, it's nothing bad.. don't worry." She asked if I worked on a certain day. Well, my bad memory I say.. do you have a schedule ? because honestly I don't remember if I did or not.. so, we get one.. we see that I did work. She asks if I remember "A certain aide coming to me about a certain resident" ... I think... Since it is sooo generalized I'm wracking my brain as to what this could be about. So, she asks the social services worker if she can "get a little more specific" .. so she tells me the resident's name and asks if anyone came to me about any issues with them. I immediately respond with "no".. because I would remember anything about this particular person.. as they are not mentioned every day. So, she looks at me and asks if I'm sure.. I say yes. So, she seems satisfied with that and goes on her way, thanks and dismisses me. I really didnt think much of it as I know most things are investigated.. wether you know anything or not.. they have to ask. Today, the social services lady comes to me and asks me if I can be in one day during the week to talk to the investigator becasue "I was one of the staff members working that day, and I was working that residen'ts hall, and she wants to interview anyone who was working that day, that shift, with that aide." I say yeah.. ill be there. So, I'm very worried. I find out that the aide in question told the DON that she reported this "verbal argument" to me and the charge nurse.. This is honestly the first I've heard about this incident.. yes i was working that side but when I went into this particular resident there were no signs to make me believe she was frustrated or even doubt anything. So, basically it comes down to this other nurse and I words against this aides.. although the aide in question had been fired immediatley. Am I making too much of this? or is this grounds for real worry?