The worst thing that anyone can do is to say "I love you", and when the other side is just melting in silence joy, misread the situation, thought that it maybe was to soon, and said "dont freak out, I wasn't serious"
Glad, this here isn't a thing (which is usually "what did you say? It wasn't serious? Why the hell then you said it?")
What a boss mannn I knew the cliffhanger was gonna be bait but he delivered at the just like we all believed he would good on you
@Jmann Did I misunderstand? I thought Shikimori-san was the one who said "I wasn't serious" referring to her talking about never wanting to wake up from the dream and other depressing, escapist thoughts
@Sollertia_ I thought of it that way as well. A long time ago she said she was scared of Izumi going somewhere far away (when the cool senpai got introduced), so Izumi thought she was referring to that and wanted to comfort her. When he said, "I will always be with you," Shikikomori understood why he was doing it and then she said, "I didn't really mean anything serious by all that."
In short, to me, you are correct.