Man proposes, God disposes.
The gate swung apart, the bridge fell, the portcullis was drawn up.
Note that in these examples the relation is not one of cause or consequence. Also in the colloquial form of expression,
I hardly knew him, he was so changed,
a comma, not a semicolon, is required. But this form of expression is inappropriate in writing, except in the dialogue of a story or play, or perhaps in a familiar letter.
[6.] Do not break sentences in two.
In other words, do not use periods for commas.
I met them on a Cunard liner several years ago. Coming home from Liverpool to New York.
He was an interesting talker. A man who had traveled all over the world and lived in half a dozen countries.
In both these examples, the first period should be replaced by a comma, and the following word begun with a small letter.