Opening Evolution - Philidor Countergambit (part five)

WHAT to do if the Philidor Countergambit is played against you unexpectedly and you have nothing prepared? This high-level game from a Canadian tournament provides one answer.
Pascal Charbonneau (2513) - Hikaru Nakamura (2733)
Lloydminster 2010
1.e4 e5 2.Nf3 d6 3.d4 f5!? 4.exf5!?
This is by no means as popular as 4.dxe5 or 4.Nc3. But it has a certain importance in that early examples of the position reached after 4.exf5!?  (Isidor Gunsberg in 1887; Emanuel Lasker in 1910) come via the Latvian Gambit, ie 1.e4 e5 2.Nf3 f5!? 3.exf5 d6 4.d4.
4...e4 5.Ng5 Bxf5
This protects against Qh5+ as well as supporting the e pawn.
6.f3 exf3?!
This apparent-novelty is not liked by Stockfish10 and Komodo10, who give 6...Be7, albeit preferring White.
7.Qxf3

Black to make his seventh move

*****
*****
*****
*****
*****
7...Qe7+??
This drops a piece. Black had to play 7...Nh6.
8.Kd1
Did Nakamura somehow miss this simple sidestep? Black is still in the game after 8.Be2 Nc6 as 9.Qxf5? (9.Nc3 is better) runs into 9...Qxe2+!
8...Qf6
Defending the f5 bishop and getting the queen off the dangerous e file, but now the a8 rook falls.
9.Qxb7 Qxd4+ 10.Bd3 Qg4+ 11.Nf3 Bxd3 12.cxd3 Ne7 13.Qxa8 (1-0, 31 moves)