Hi Bobbitworm,
I can give you reasons why I think it is actually a short-billed:
In summer plumage, Long-billed are normally much darker uniform red; this is more orange toned.
Patterning on coverts and tertials has broad pale stripes and irregular barred patterning. On Long-billed these are normally plain or lacking the contrast of SBD.
Barring extends past the legs and under the belly. on Long-billed, the belly is normally unmarked.
The eye is towards the top of the head, so appearing above the line of the bill.
I only come across Dowitchers on an annual basis when leading tours in US and Central America, but, and I'm happy to be corrected by my learned friends in North America, I think this is Short-billed.
Stu