Yep , bill colour is one of the most important characters here , and when looking at the photos , I agree that it seems to have a darker orangey yellow colour than the bills of the neighbouring fuscas. The yellow “lip” on the upper mandible is – as Kent states – a good character on stejnegeri , and in some of the pics it actually seems to show just that. However , it can’t be seen on some of the other photos , and I’m not sure if that is due to the poor photo-quality or if maybe what looks like a brighter yellowish “lip” is indeed reflections of light? To complicate matters further , Sebastian – who has actually seen the bird – describes the bill as "more flesh-coloured than the more yellow-billed fuscas”. So , on the basis of the photos I would agree that the overall colour is looking good for stejnegeri – though maybe without the yellow lip (?) ; on the other hand , Sebastian’s statement about a flesh-coloured bill (as I understand it) would point more towards deglandi , I think!
Another character that Kent mentions is , how far out the black feathering/bill base reaches on the bill. On the picture above (top , middle) it certainly seems to go out quite a bit , but on others (mainly Jan’s) this is much less obvious. Likewise , the head shape seems to vary a lot depending on what pictures you’re looking at. On the two leftmost pictures above , it looks like the forehead has a rather flat/linear slope with no distinct angle on the bill. On some of the other photos (e.g. the top , middle one) the forehead looks rather steep with an obvious angle to the bill , so I think it is difficult to conclude anything on that from the photos. Regarding the “nostril-knob” , I agree that the wattle/protuberance on top of it can vary , but the knob itself is usually quite prominent. In real life this should be possible to see , but again the pictures are inconclusive in my opinion.
All in all I agree , that judging from the photos there’s a really god possibility that this could be a stejnegeri. However , different pics seems to be telling different stories , and are even inconsistent with eye witness accounts. So , I think we need better quality photos to say anything for sure , or else leave it up to the birders who have had the benefit of seeing the bird “live” make the final call.