To intervene on behalf of DS1 at School

I have name changed for this to avoid the school being identified as I have posted about which school DS1 attends in the past. However I have been on Mumsnet for years albeit not as a prolific poster.

DS1 in year 9 has had a tough couple of weeks. Some kids from another set accused him of selling them a photograph/video of a maths progress test which his set did before them when they got caught out cheating. It transpires that the completed tests were found on the desk in a classroom, DS1’s was photographed and distributed by someone from within that class, school have investigated, found the truth and dealt with the culprits without any intervention required from me. Throughout most of this DS1 was strong, stuck up for himself and had a number of friends support him in getting the truth known.  
However, there is now a backlash from the culprits and ‘most’ (according to DS1 but this may mean a couple of ring leaders and a few hangers on) of the rest of the set towards DS1 as they are in trouble and the whole class had to retake the test. He is starting to feel like everyone hates him and it's getting him down. 
My dilemma is should I intervene and tell his form teacher what is going on now or should I rely on his resilience to get him through it. I am worried about making it worse and as it's almost the end of term I'm tempted not to as it will probably be forgotten about over the Xmas break.

Trying not to make this too long but to give a bit of context and to avoid drip feeding one of the ringleaders is already known to me as a troublemaker as his name crops up in connection with almost every issue DS1 has told me about in the past. e.g. he has made prank calls including some to me and has in the past sent me inappropriate texts about DS1 having got hold of my mobile number.

I am usually quite hands off about school issues as I like the DC to be confident they can deal with things themselves and so far this strategy has worked but I hate seeing DS feeling so low and frustrated. He has access to counsellors as school and knows that there is always someone he can talk to and I have told him to make use of this if he feels he needs to.

Wwyd- would you intervene at this stage and to what extent. Ie just a brief email to form teacher letting him know that DS1 is struggling or would you ask for a meeting to discuss the issue a bit further.