I recently read starting strength and watched the instructional DVDs that go with it. I was blown away by the squat DVD and was excited to get down the gym and put what i had learnt into practice. I warmed up, started off with BW squats (shoving my knees out) then just the bar, carefully using all the things I had learnt. It felt great and I started to put some weight on the bar gradually increasing so I could still concentrate on technique; 40, 60, 70, 80, 90kg. They all felt good so I went for 100kg (which is my prev PR at 2 reps). I was training alone so thought it only sensible to ask for a spot from someone experienced. I asked a guy who a i'd seen a lot of people go to for help/advice. I did 4 reps with him behind me, everything was right, hams touching calves, knees out at the bottom, hip drive, chest up, chin down looking at the floor, EVERYTHING felt good from my feet position to where the bar was on my back. I racked the bar and turned round and was told I was doing it all wrong because I went below parallel!! He told me to strip all the weight off and start again with just the bar going exactly to parallel!! WTF!