Odd that Mr Ellacott, who was less than 100 yards from the crash site, never mentioned seeing anyone else as he proceeded towards the wreckage. He did state however that visibility was " nine or ten feet maximum" - which would have given the "SEAL" a few problems in locating the wreckage.
Quite right. More importantly, nor did those who could see 500 yards.
Perhaps the SEAL approached from that direction? He'd have had perfect visibility and time to orientate himself amongst the wreckage.