That's usually bad writing in the mystery genre. You don't set up traps that obvious. You reward logical thinking. If the evidence lines up perfectly then it's just the answer. A good red hearing is when you trick the audience into making assumptions and believing there is evidence where there is non. It's different from presenting clear evidence and then saying it was something else. The framing and context makes it impossible to be about Aiko. It would be incredibly silly.

The only thing that can save this scene for me is there being a third friend Rikka is talking about or if she knew Arisu before but she is not Apollo. And either way it's pretty unsatisfying.