From Day 1:
viewtopic.php?p=1038919#p1038919Specifically:
both animask and salvage brought up the guardian angel when talking to me - werewolf tell
animask and salvage both refused to claim - werewolf tell
salvage even went so far as to say that he wouldn't claim even if town was going to waste a lynch on him
Day 1 is pretty much a goldmine of information, now that we know for sure that animask and foulcoon were wolves, and we can quite safely assume that Chris was also a wolf due to his actions late day 1. I would highly advise rereading d1 and d2 keeping that in mind.
Things to notice: animask defending Salvage and voting Chris, Salvage bandwagoning on Chris, foulcoon attempting to defend Chris and distance himself from animask and Salvage.
Day 2, Two is pretty much confirmed town. On Day 1, Two provided a list of the roles he received and more importantly, the roles he did not.
viewtopic.php?p=1041102#p1041102Claiming seer before that information went public would have been an extremely risky move, with the high chance of a counterclaim. But afterwards, most of the risk involved is gone, with several roles being all but confirmed with the confirmation of Two being town.
As for reasons to why Salvage claimed seer instead of civilian: for one, there were already 4 civilian claims, for two, Salvage had already refused to claim so claiming civilian after that would never work, and for three, claiming an information role moves him down the systematic lynch list, prolonging his survivability. Salvage was forced to claim an aux role, and seer would be by far the easiest to emulate. You could also consider the fact that this game has gone on for so long, unable to successfully lynch a wolf. I'm a civilian and have been expendable the entire game. Salvage claimed seer and became the last on the lynch list.
