I met a guy flying for a major freight company in the US and he was bragging that he had 35,000 hours, almost all PIC. He was wearing F/O bars. He was 30 years old. A small discussion showed that he logged all his flying as PIC since he had an ATP (after you get 1500 hours you can get an ATP in 48 hours, ground and flight tests included). He logged all his time, off-duty sitting in the back, or in the bunk, and I would not be surprised if he logged his dead-head sectors as well.
Point is that the FAA would accept this as logged, nobody would question it. The Asian carriers are worse (maybe not SIA) because they simply don't understand the complexities of the rules.
Only the Brits and the other Euro-centred countries even worry about such a thing. When competing on the open market for jobs, you will always be pipped by those who don't care for the rules.