Statistically speaking, everything points to human interference.
My theory is that the government was planning to cut funding, and to stop that from happening someone deliberately created the interference. That's more likely than aliens going extinct after sending one single message.
Not sure about radiation, but I once tried to boil an egg in the microwave and the microwave exploded. For a second, I thought the chicken had secretly developed human-level intelligence and planted an explosive inside the egg to get back at those stealing its babies. That was my "wow" moment. Then my dad confirmed it was my fault and compared my intelligence to the chicken's.
A person is flying a hot air balloon and realises he’s lost.
He lowers the balloon and spots a man down below. He shouts:
“Excuse me! Can you help me? I promised a friend I’d meet him, but I have no idea where I am.”
The man replies, “You’re in a hot air balloon, hovering 30 feet above the ground, somewhere between 40 and 41 degrees north latitude and between 59 and 60 degrees west longitude.”
“You must be a Prompt Engineer,” says the balloonist.
“I am,” replies the man. “How did you know?”
“Well,” says the balloonist, “everything you told me is technically correct, but it’s of no use to me and I still have no idea where I am.”
The man below replies,
“You must be a Vibe Coder.”
“I am,” says the balloonist. “How did you know?”
"Because you don’t know where you are or where you’re going. You made a promise you can’t keep, and now you expect me to solve your problem. The fact is, you’re in the same position you were in before we met, but now it’s somehow my fault!"