I'm on a RTW ex-AKL and received a *CLR* for all six North American AA segments even though I had only flown one of them on AA before. Perhaps another factor has to do with who issued the ticket and where it was issued. Mine was issued by AA in the US and paid for with a credit card.

I was flagged for a gate check recently when traveling on a ticket issued by DL as the result of a misconnect on a DFW-LAX segment. There were about 6 of us that DL placed on that AA flight and all of us were checked. My guess is it was caused by a last minute ticket issue from a "foreign" (non-AA) source with a non-standard payment method.