Yes, you are supposed to lose the first fight with the biker. In my case, he just regenerate his Health and no matter how hard I tried to win, I end the fight losing every time.
Game is very nice, some of NPC dialogues are still not fully translated to English. There are some places where you can stuck or broke the game animations/moving etc. but if you don't experiment too much and don't walk in not necessary places, you shouldn't get too many bugs.
There are also one more fight I know that is impossible to win with 1st try and you'll always end up losing so don't worry too much about winning or loosing. Sometimes you may want to loose on purpose to see new sex scenes.