Better safe than sorry???

I have been having a series of jabs prior to my summer trip. Yesterday was the final round and on the cards was Hepatitis A, Rabies and Japanese Encephalitis. The doctor is very friendly and also likes to speak English and when it comes to medical Japanese, well...er.. I am happy for him to do the talking. I roll up the sleeve of my T-shirt... One down, two more to go. As he is about to stick the second needle in he tells me it is the rabies one.. Out of curiosity I ask what the first was. He looks at the sticker now attached to my vaccination record sheet and his face was a picture. Oh 'Sh.....ugar'. I feared the worst. That was Hep B, the nurse made a mistake when preparing the needles! "And the doctor an even bigger mistake not checking" I muttered to myself. I could take action I suppose if I had the mind to, but it's not my style and besides, there is no harm done. The standard procedure for Hep B vaccinations here is three shots. I am no doctor but I was good at maths once - so does that mean I am a third protected against Hep B?