Why is "golpeara" used here?

[createdamadman]

In the example below, the person talking is a witness to a traffic accident and knows what happened. So, why is she using the imperfect subjunctive "golpeara" instead of the preterite "golpeó"?

[AngelicaDeAlquezar]

This use of the preterite subjunctive is often found in journalistic and literary styles.
It talks about an event that happened before the "main" action.
Maybe it would be better to have said "...después de que un coche lo golpeó", but we hate repetition and repeating the tense might make it confusing to know what happened first.
Also we could say "...después de que lo había golpeado un coche", but the formula sounds rather long, so the trade-off is to use the preterite subjunctive.

- El discurso que pronunciara ayer el candidato generó muchas críticas.
The speech that the candidate made yesterday provoked many critical opinions.


- Un vendedor de teléfonos se volvió famoso luego de que cantara en un concurso de talentos.
A phone salesman became famous after singing in a talent show.


- Por la noche tuvo un mareo similar al que sintiera por la mañana y decidió ir al médico.
At night he felt dizzy, the same way he had felt in the morning and decided to see a doctor.

[wrholt]

It's an old usage of the past subjunctive (or imperfect subjunctive) with the -ra endings as an equivalent of saying the modern pluperfect tense (lo) había golpeado = "had hit (him)".

In one of my advanced language courses I was taught that this usage is almost completely obsolete in modern writing EXCEPT in news reporting and some literary styles; journalists sometimes use it instead of golpeó or había golpeado for the meaning "(had) hit".

This usage is the last remnant of the original meaning of the Latin verb tense from which the past subjunctive with -ra endings evolved: in Latin the tense was the pluperfect indicative.

By comparison, the Latin verb tense from which the modern Spanish past subjunctive with -se endings evolved was the Latin past subjunctive tense.

This evolution of the Latin pluperfect to mostly merge in usage with the Latin past subjunctive into the 2 sets of endings for the Spanish/Castilian past subjunctive is specific to Spanish/Castilian. In Portuguese, for example, the equivalent forms with -ra are the simple pluperfect tense, in contrast to the Portuguese past subjunctive with -se.