No matter how many commas there are in a transcript nor how many different ways they are used, there are, in fact, only two basic ways that we use commas: commas to separate or commas to set off. We use a single separating comma to push two elements apart, or we set an element off with a pair of commas. Every comma rule fits into one of these two uses of the comma.
...was a lively, energetic debate...
...saw the difficult, difficult time he was having...
...We sent it on Friday, and it was received later that weekend.
...on Friday, May 9, during the early morning hours...
...her family doctor, Dr. Ryan, was...
...came in with Ross, not Hanson, to the reunion...
While there are many places that a single comma needs to be used to separate two elements, there are places where you must either surround the element with commas or use no commas at all. This is where the "two commas or no commas" expression comes from.
Two or none:
...I noticed somewhat later, that he... :-(
...I noticed somewhat later that he... :-)
Two or none:
...Are you saying then, that you... :-(
...Are you saying, then, that you... :-)
Two or none:
...And again, we were... :-(
...And, again, we were... :-)
...And again we were... :-)
So though you often need a single separating comma between two elements, you are often choosing between using two commas or no commas.
Happy punctuating!
Margie