You analysed his character so well. The writers are exploring his jealous and possessive side again by bringing misunderstanding track . I can't believe he is this insecure even after knowing how she risked her life to save him from terrorists.
It’s simple ITV logic. When hero sees heroine physically intimate with someone else he misunderstands. After that no logic works. In ITV physical intimacy is given the number one priority.
I remember in Udaaniyan ( a show in Colors) hero had an affair with vamp but SR only with heroine- and there no matter how many dates he went with the vamp, it was not called as crime. I mean still viewers loved the lead couple.
So here that’s exactly is happening. No matter how much Gungun did for Anubhav, to save him from the terrorists a kiss breaks all his trust.