It has been alleged that the actor was responding to bad language from NRI businessman Iqbal Nadim Sharma, directed at Kapoor and other industry figures with whom he was dining.
Although not officially representing the star, Bollywood PR guru Dale Bhagwagar told Digital Spy: "Saif has the class of a gentleman. I've heard that the NRI guys used words like 'wh*res' and 'prostitutes' for his actress friends and provoked him to argue."
The Kal Ho Naa Ho actor - who was reported to have injured Sharma in the altercation - was acting in self defence after he was himself attacked, Bhagwagar stated.
"In spite of such filthy language, Saif is [believed] to have only argued and not raised his hand, till the NRI's father-in-law is said to have suddenly hit him on the neck," Bhagwagar added. "I'm told that is when he reacted in self-defence."
Bhagwagar rose to prominence in Bollywood PR during 2007's Celebrity Big Brother, as Shilpa Shetty's spokesperson.
Ali Khan and Kapoor will be seen next in Agent Vinod, releasing on March 23.
Watch the Agent Vinod trailer below: