it has been suggested to me that I shouldn't watch it until i'm well through my training
This is the ostrich method of training. What you dont know can still hurt you.
Not sure from your post if you are familiar with the NTSB accident database. This lists every US R22 and R44 accident (more thna 400 IIRC), with supporting details, and in most cases, a probable cause. Far more useful, IMO, than the Robinson video (which is still definitely worth watching more than once). Google NTSB aviation database for a link.
At the risk of restarting a war, the R22 is perhaps the MOST demanding light civilian helo in the fleet. It is in your best interest to find out as much as possible about this acft (assuming you are training in it.) The R44 is less demanding, but shares certain characteristics.