Very interesting.
My experiences with IG show some similarities and some differences.
Difference - There is a pronounced self-effect on me. I become more polite and considerate.
Possible similarity - I was using IG with a professional in an industrial factory setting. We had a good talk and a meal together. When we got back down to work the guy left the area and got into an altercation with a factory worker, coming back to my area trailing the worker. He was using foul language towards the worker, who was none to happy himself. I took some steps towards calming them down, and both were respectful towards me even though they were highly agitated towards each other. I did wonder if the IG influenced the professional’s behavior with the worker. Your observations of building tension after exposure may indicate an effect of a similar nature.