The reason why its not a good idea to do more than 1 ml of juice in the shoulder is because of the very reason we are discussing it now.If I had a dollar for every guy in my gym who injected more than a ml into the delt and had problems I would be a rich man.Oil based inj take longer to dispurse than water based inj the delt is only a small muscle the glute is the largest.With Glutes u have less chance of hitting anything shoulders are full of veins capillaries etc so why take a chance?