Yes so the air is at the plunger side. To cause an air embolism, upwards of 15cc of air would have to be injected directly into a vein. With the size of a slin pin and the size of the tiny air bubble, injecting a bit of air sub q would cause no issue at all. Bear in mind that you only want to draw enough air to clear the syringe of the compound being injected, which takes very little.