When you inject you are injecting a lot of oil. Believe it or not some of it may be passed through the large intestine and shit out or even sometimes it goes through the kidneys and is pissed out. I can't believe nobody has noticed this before.
You have not wasted a shot. Most of the steroid is pulled out of the oil and sent to the liver by the blood. Everyone loses excess steroids into your urine. Hence, piss test.