Both of them are responsible for their tiff.. Believe it or not Sid became kind of over confident about his position and was sure enough that Asim will not be able to play without his support that's why whenever Asim tried to put forth his point Sid always discouraged him kind of mocked him and his " Let's fly solo" Rant had become too much to handle ... It's Asim's nature to build up things within his heart and we all know when the balloon was burst..
Sid was for sure a very strong support for Asim.. When the guy was mocked by paras for no reason Sid gave the shelter of his friendship and together they were a deadly combo... If Sid supported Asim through his thick and thin then so different Asim.. He too was very generous from making sure he get his rotis to controlling his temper.. Asim didn't initiated any bond apart from their own group because Sid was not comfortable.. He didn't betrayed him in any sense as some people here believe.. But both of them being a strong personality tiff is bound to happen.. But due to the build of months by Asim and pushes by Sid it became very ugly
Their was no betrayal in their friendship but they themselves ruined it.. Sid being the elder one should've listen to asim's point of view and not mock him ... Asim should also have let go the matter
Such lever of anger can come from a very strong bond.. They still can become friends but both of them have to handle things smartly .. Sid has to learn to respect and Asim too has to let go his grudges