I can't agree. I have never had this happen to me nor have I ever heard anyone mention a needle breaking off. Has anyone?
IMO, it is better to use a pin that is the correct size and sits flush on the skin so that after aspirating you don't push it back and forth and end up puncturing something.
5/8 is a perfect size for most delts...
You can try sliding the skin to one side to prevent leakage... this is what I usually do. Slide it to the side, administer the shot, remove the pin and then let go of the skin... and let it slide over the site to stop leakage and possibly bleeding. Obviously it won't work when the site is on one of your arms (delts, tricpes, biceps)...