Family Behavior during a code

I work as a float RN at an acute rehab hospital. I have worked there for 7 years. Two days ago, I had an elderly patient who had had a stroke. He had multiple co-morbidities. The son was in the room. They had been admitted the prior day. In report that morning, I had been warned that family was very difficult. I found the son to be suspicious. He demanded I explain each medication and why I was giving it. He chose the meds to be given or held. I complied with his requests. My patient load was demanding. From 0630 until 1350, I never hit the restroom or took food or drink. We have Spectra-link phones. At 1350, I did go the restroom and then spent 15 minutes in the breakroom eating. Shortly after 1400, I finally sat down on the unit to chart (since I had not had a chance to chart all day). At 1425, I heard a shout from my patient's room. The son had come into the hall shouting, "I need help, he's turning blue". A tech ran in the room, hit the code button. I was in the room within one minute. As the room was filling with the code team and additional staff, the son kept shouting that "I kept calling the nurse and she would not come". The pt was in full arrest and a code was conducted with eventual ROSC (about 15 minutes in). He was transferred to ICU. I was so horrified by the son's false claims that I had a charge RN look at my phone, both missed calls and received calls. There were no calls from that room to me between the time I was last in there (noon meds) and the code. I also took pictures of the missed call and received call lists on my personal phone. This has made me very nervous. I have malpractice insurance. What steps should I take now?