The second recording sounds like a Wood Thrush giving one of its contact calls. Both recordings seem to have American Goldfinch calls. The first recording also has a single low note that sounds like a call of an American Robin.
Bicknell’s Thrush can show rufous tones in both wing and tail, and I realize that rarity and range make that a long shot. It appears to be a young bird based on the pale tips to its wing coverts. Hermit has buffy flanks compared to Bicknell’s/Gray-cheeked grayish flanks.
Interesting bird, indeed.
There seems to be a difference of opinion about the where on the bird this white area is. The Cornell Lab of Ornithology's Birds of the World reference (https://birdsoftheworld.org/bow/species/naswar/cur/appearance#idsum) refers to it as "lower belly", and the USFW Patuxent Wildlife Research...