（如果只計算法庭內發生的事實）點解陳振聰會淨係比人告「偽造文書」而無連帶嘅「發假誓」「妨礙司法公正」之類嘅？

There are many reasons:

1. It is customary for the prosecution to prosecute crimes associated with a higher maximum penalty.

In Chan's case, forgery carries a maximum sentence of 14 years (he got 12). The maximum for both perjury and perverting the course of justice is 7 years.

2. When multiple offenses are resulted from a single incident, the court is very likely to impose sentences concurrently.

In Chan's case, with or without perjury and/or perverting the course of justice, Chan will still get the same amount of sentence.

3. A consequential relationship exists among the offenses charged and offenses omitted.

In Chan's case, without the forgery in question, Chan could not have committed both perjury and perverting the course of justice.

一罪不能二控，入罪是審前控告，被告供詞態度行為只影響審判基準，不是控罪。