Donaldson gifted the match away with DF's and unforced errors in the most important points, but it's tough to blame him honestly. It must be very annoying to face someone which only game is based on servebot like there is no tomorrow, specially for young players, not used to this kind of "tennis" yet.
That 0-30 game Isner saved with 4 straight 500 kmh serves on the line was one of the most disgusting I ever saw.
Isner hot run of form during this US summer is kind of a fraud though, he reached this M1000 SF by beating the #47, #175, #87 and #60 of the world.
During his title in Newport he beat the #201, #203, #142 and #249. In Atlanta he beat the #68, #129, #22 (Muller) and #42.
Lost to Delpo (#31) in Montreal.
So, 870 points with only one top 40 win.