Every article I linked refers to manufacturers saying not to use them. Why isn't that good enough?
It is good enough. That's not what is happening here.
You lashed out at someone saying "children may die" because of him. For that you need strong evidence, not just the advice of a glorified mommy blogger?
If you want to tell us that using a car seat beyond its expiration date is dangerous because manufacturers haven't tested for their safety and efficacy? Go ahead. But please hold back on the dying babies talk and righteous temper tantrums when you have no evidence that such a seat has ever caused even one injury, let alone death.
This is not to knock the car seat lady - she knows a heck of a lot about car seats, and no one here claimed she is an idiot. If I were her, I'd also advise against using expired car seats. But no where does she yell and scream at people implying they are potential murderers if they don't follow her advice, or if their child wears a coat in a car seat.