Sorry but I'm still not getting it. As far as I can see, the only difference is that the latter version mentions the exception for the through check in of bags as mentioned in my post, as mentioned by chris1979, it signals no difference whatsoever when it comes to itinerary protection in the case of separate PNRs.

As for the other quote, as mentioned by others, it pertains to connections (ie different flights in a given PNR) and for that matter, BA will also definitely protect your flight if you miss your connection arriving from a non-OW flight as well, that is the whole point of connecting itineraries.

Again, I see nothing in the different sources above that gives any suggestion that BA would protect your flight if you arrive from a flight on a separate booking from a OW booking. If we are in a "compare and contrast" exercise, I suggest comparing to the phrasing used by AA. There is simply no similar exception mentioned as part of BA CoC:

AA to/from AA or a oneworld® Carrier:
If a customer is holding separate tickets on AA or another oneworld carrier, customers holding separate tickets where travel is on oneworld airlines should be treated as through ticketed passengers. In the event of a disruption on the originating ticket, the carrier responsible for the disruption will be required to reroute the customer to their final destination. The ticket stock of the second ticket must be of a oneworld carrier, eligible under the Endorsement Waiver Agreement. You may contact AA Reservations 1-800-433-7300 (U.S. and Canada) or outside the U.S. and Canada, reference Worldwide Reservations Numbers for additional information if the separate ticket is for travel on a oneworld carrier.

[http://www.aa.com/i18n/agency/Bookin...kt_policy.jsp]