叫ぶ and 怒鳴る: loud calls and the context of a shout
Compare a warning cry, a shout on stage, and an explanation given instead of yelling, without inferring anger from volume or a performer’s feelings from a scene.
Calling out a warning or a name
「危険に気づいた彼は皆に逃げろと叫んだ。」 identifies someone noticing danger and shouting for everyone to run. Read the person, audience, and shouted content together.
「山頂で友人の名前を大声で叫ぶ。」 describes loudly calling a friend’s name from a mountain summit. 叫ぶ involves a loud utterance, but loudness alone does not establish anger.
A shout directed at someone
「舞台の隊長が部下に向かって怒鳴った。」 describes the captain on stage shouting at subordinates. The audience of the shout and the stage context are both stated.
怒鳴る can involve calling loudly or shouting in a scolding context. A shout within a stage scene does not establish the performer’s actual feelings.
The action performed instead of yelling
「怒鳴る代わりに、落ち着いて理由を説明した。」 describes calmly explaining the reason instead of yelling. Explanation is the action stated as performed; 怒鳴る supplies the alternative it replaced.
Do not rank 叫ぶ and 怒鳴る as two fixed volume levels. Read whom the utterance addresses, whether the context involves scolding, and whether another action takes its place.
What action is stated as performed in 「怒鳴る代わりに、落ち着いて理由を説明した。」, and does the appearance of 怒鳴る mean that yelling occurred?
Show the answer and why
The stated action is calmly explaining the reason. 怒鳴る identifies the alternative replaced by explanation, rather than an earlier action in a yell-then-explain sequence. Likewise, volume or a stage context alone does not prove actual anger.