I learned a lesson last year being helpful. I was diving with a guy that was on his first and second dives after OW, and he clearly didn't have buoyancy control down. We were at about 30 feet when he put some air in his BC... he put in too much, and started to go up, got confused about which button did the dumping and pumped a bunch more air in his BC. He was a little below me when this all started and as he went past I grabbed the back of his BC and dumped mine (I couldn't reach is shoulder dump). We went up, but not too fast so I just went with him, figuring I would help him figure it out on the surface. He surfaced, and I popped up just behind him. He turns around and says "Hey, what are you doing here?"
I started to tell him what was up, but all I got out was "Well, I came up with you" when he grins and pulls his shoulder dump and sinks like a rock.
This is where I made my mistake. I was so intent on following him back down in the bad vis (all I could see was his bubbles) that I forgot to clear my ears until way too late. Cost me about a month of diving from an injured ear, plus a trip to a specialist to get myself OK'd to dive again.
Looking out for your buddy is great, but you can't let that get you task loaded enough to get yourself hurt instead.