He missed an apostrophe that you didn't catch: "important person's cat", i.e. a cat owned by someone who would be vocally unhappy their pet was killed. This as

He missed an apostrophe that you didn't catch: "important person's cat", i.e. a cat owned by someone who would be vocally unhappy their pet was killed. This assumes that the dosage of aspirin is fatal to cats, which is not something I'm sure of (or care about enough to research).