We first tried yesterday morning, arriving at 8:30 which was apparently not early enough. Not a wasted trip though as we saw several dozen species at what is a new location for us. This morning we got there at 7:15. Danielle had an initial spotting of the flycatcher at 7:30 but not long enough for us to get a positive identification but enough to be fairly certain it was not the Ruby-Crown Kinglet which has a similar face as shown below.
This bird is a small member of the Empidonax genus, all of which look very similar. Sibley's lists the primary field marks as short narrow dark bill, distinct olive vest, long primary wing projection, and short narrow notched tail. To be honest, I am taking the word of the more experienced birders as I would not be able to make a definitive call.