[greymule]

Well, I was assuming the contact to be "a real collision and not just a bump," something in between malicious contact (a deliberate crash that warrants automatic ejection) and incidental contact (simply trying to tag the base without sliding). On the other hand, Fed may not recognize anything in between. A collision might have to be either malicious contact or nothing, no call of "runner out for colliding with catcher, but it wasn't malicious so the runner is not ejected." Perhaps that's why BRD says, "When the runner has time to 'get down,'--and doesn't--if the fielder is knocked off his feet, don't worry about 'intent'; call it a malicious crash and eject the runner."

PS. jicecone, I think you meant rule 8-4-2b.