By using てもらう, it is conveyed that the other is doing something helpful or useful for the action recipient's sake, whereas using the passive られる there is no such nuance and it is more neutral. In the following example, though both sentences are grammatical, the first seems more acceptable to me because this feeling of helpfulness or usefulness is congruent ...
The passiveness here has nothing to do with てしまう. Your sentence uses the verb 捕まる which means "to be caught". The passive is inherent in the verb choice. Compare this with the verb 捕まえる which means "to catch". Japanese has a lot of verb pairs like this.
The てしまう ending merely adds a sense of regret as you correctly stated.
In this case it is
And the 怒られる is just a standard passive of “BがAに怒った” (B ‘madded at’ A) → “AがBに怒られた” (A got ‘madded at’ by B).
I think the terms “indirect passive” and “direct passive” are generally misleading. Basically when the subject of a passive sentence is a human, ...
Simply let's take "somebody eats something mine" situation.
(1) ケーキを食べられた (I really wanted to eat it! but) The cake was eaten.
(1) is normal suffering passive example. (2) is negative form as the way you showed, which is expected to mean "I really wanted someone to eat it but the cake wasn't eaten."
But (2) simply sounds "I couldn't ...