For full context, see here exercise 3: https://www.docdroid.net/rHnvU6R/2.pdf
The sentence in question:
First, my attempt at translation: "I came back, because when I went to the station, with the train being on hold because of the snowmasses they said that within this day, going to the other side (=going to the destination station) is impossibru."
In my opinion, 帰ってきたんだ sets the tense for the rest of the sentence, as the speaker is talking exclusively about things which happened in the past. Therefore, I would also expect the "...たら-clause...clause2" to show another past tense in clause2, which also would quite fitting for the situation of "I did X and in consequence I discovered Y" -> 家に帰ったら、猫がいなかった。
However, here っていう sets the tense of clause2 to present. As far as I can remember, it is also grammatical to say ...と言いました or って言った. So I wonder what the reason might be that present tense is used here? Also, how does it change the meaning of the sentence, if it does at all?
In a question dealing with a similar problem, some of you said that if the context is strong enough, the tenses can be used however one wishes. Is this the case here as well?
One sidequestion: Why is it 帰ってきたんだ ? What is this 来る doing here? I can only imagine two meanigns: Either 来る marks that the action is going in the direction of the speaker like 兄が帰ってきた。 Or it marks that someone performs an action and then immediately returns like スーパーで牛乳を買ってきます。 I think the latter makes more sense, but it seems a bit strange to me because until now, I only encountered cases where the speaker tells us about a thing he is about to do/going to do in the (near) future with the intent to return immediately after completing that action.