Smarter than a 5th grader? Verb tense.

Hello, Gada.

First things first. There is no rule, there has never been any rule that requires consistency in verb tenses. This old canard is known as Sequence of Tenses or Tense Concord or probably some other names.

Tenses are chosen to express the meaning that we want to express. There could be no other way for language has to allow us to express all possible thoughts, does it not? You noted that yourself when you said, "The second sentence seems to make more sense".

Both, obviously, are correct. There are many reasons that we "switch" tenses. Tense is more than just a marker of time. We use past tense FORMS, for example, to express politeness/deference/a softer manner/... .

In writing, we often take a more conservative approach, which is likely what your son did here. In speech, we often tell finished stories with the present simple and that particular grammatical flourish is done for semantic reasons. It makes our story more NOW, more alive, I guess, since we all do it, more interesting.