If you are talking about Technical Analysis in general, we would need to write a book to answer that.
As for Technical Analysis applied to Bitcoin, just look at the date when the predictions were made, look at the graphs and compare. During the last couple of months:
He wrongly predicted a short term rally starting at $14 at the end of July
He correctly predicted the short term fall to $6 at the beginning of August
He has been predicting a long term up trend for two months that hasn't happened yet
Overall, I think his analysis are well documented and based on market indicators that work very well in other markets. However, I am not sure if the Bitcoin market got to the point where Technical Analysis plays an important role for price movements. No one can really tell because this is not an exact science.