The crowd listened to Paul until he said this.
Shouldn't it be "had been listening"?
The action "the crowd listened" preceded the action "Paul said" and the listening must have taken some time.
Why, in one case, you say "They had been walking outside until the weather turned bad" and in another case you say the first part of the sentence using the simple past tense?
How do I choose between the two tenses, the past perfect continuous and the simple past?
For what it is worth, I intuit this has to do with listening being a continuous activity— thus warranting a progressive tense. For this reason the past perfect tense as well as the past continuous tense is the proper tense. Of course meanings of these two tensed versions differ.
This is not to say listening would never take the past simple. Specifically, this means it's restricted to a point in time only. A person might say to another person I listened to you the last time, now you should listen to me.
I think the bottom line is that tenses can be tricky as there can be overlap at times.
I was interested in this question because I recognised its context. It is from the Bible, specifically from Acts 22:22. The Paul in this sentence is the apostle Paul, and he is talking to Jews in Jerusalem, telling them why he became a follower of Jesus. At this point the Jews stop listening and try to kill him. He is taken into protective custody by the Roman guard, and the story continues. You can find the full account here.
Because of this there may be other factors relevant to the question. For example, we are talking about a translation of an original Greek text into English. Therefore a choice of tense may depend on more than simple English usage.
But if we limit ourselves to the basic question about tenses, the important thing to understand is that English has many different valid ways to describe the order of events in a story.
The OP asks:
The crowd listened to Paul until he said this.
Shouldn't it be "had been listening"?
And the comment reveals an assumption: if action A and B are both in the past, and action A comes first, we have to use the past perfect tense. But this is a bad assumption. We can use the perfect tense, but we don't have to use the perfect tense. For example:
The crowd had been listening to Paul, but then he said... (This suggests a change in crowd mood. The comparison is not between the listening and the saying. It's between crowd response before and after Paul's speech.)
The crowd listened to Paul until he said... (listened is simple past, and the writer would choose this if that's all he wanted to say: They were listening. But the order of events is made clear by until.)
The crowd listened to Paul. Then he said X, and they stopped listening. (A bit artificial, but the order of events is clear, even though the three verbs (listened/said/stopped) are all simple past tenses. The order is determined by then and and, together with the word order.)
Conclusion: Often a story is told using the simple past tense, but using conjunctions, prepositions and word order. Other past tenses, such as past perfect or continuous perfect, are available but definitely not required.
Appendix
As a further example for those who are interested, the following text is from the Bible story referred to above. I have marked every primary verb in bold, and you will see how many of them are in the simple past tense. In fact just one is in the perfect tense, and yet the flow of the story is crystal clear.
22 The crowd listened to Paul until he said this. Then they raised their voices and shouted, “Rid the earth of him! He’s not fit to live!”
23 As they were shouting and throwing off their cloaks and flinging dust into the air, 24 the commander ordered that Paul be taken into the barracks. He directed that he be flogged and interrogated in order to find out why the people were shouting at him like this. 25 As they stretched him out to flog him, Paul said to the centurion standing there, “Is it legal for you to flog a Roman citizen who hasn’t even been found guilty?”
26 When the centurion heard this, he went to the commander and reported it. “What are you going to do?” he asked. “This man is a Roman citizen.”
27 The commander went to Paul and asked, “Tell me, are you a Roman citizen?”
“Yes, I am,” he answered.
28 Then the commander said, “I had to pay a lot of money for my citizenship.”
“But I was born a citizen,” Paul replied.
29 Those who were about to interrogate him withdrew immediately. The commander himself was alarmed when he realized that he had put [past perfect] Paul, a Roman citizen, in chains.
