Infohunter: Well, I see it's been a good six months since this discussion took place. Nevertheless, I'd like to put my two cents in here.
Not only Chernev, but a lot of other writers as well, have given only the first seven moves of this game, as though that had been all there was to it. One writer (just now it escapes me who it was) did say, after giving these seven moves only, that Black struggled on for a few moves but then resigned. That is borne out in the game score as given here.
I can understand these writers' thinking here: The idea is to show the essence of this game-become-opening-trap, and to omit the "mopping up" portion. Unfortunately, this thinking is erroneous here, since it suggests to the student that White will simply pick off one Black Knight or the other on move 8, regardless of what Black does, thus winning easily. This just isn't true.
Andy Soltis comes to our aid here, with his 1978 book <Chess to Enjoy>. Soltis tells us that Black should not resign at move 7, since he has a potentially strong counterattack with 7...e6. Note well that this is <exactly> the move Black makes in the game shown on this page. Further, we see that in response to this, White does not play 8.fxe5 right off, but rather Qd4. Suppose he takes the Knight immediately?
Soltis gives us the answer: If 8.fxe5 Qh4+! If now 9.g3, then 9...Qe4+ wins White's King Rook, leaving Black the Exchange to the good. So we continue 9.Ke2 Bxc5, and now Soltis gives two possibilities:
A)10.Qd3 Qf2+ 11.Kd1 Nxb2+ 12.Bxb2 Qxb2 13.Qc3 Bd4, and here the White Queen Rook falls.
B)10.Nc3 Qf2+ 11.Kd3 Nxe5+ 12.Ke4 Qf5#.
So we can reasonably conclude that those writers who end the game at move 7 unwittingly mislead the student by doing so, since we have seen that White would either lose material or be mated as a result of capturing the Knight at e5 immediately after Black's 7...e6.
It will be seen that White's 8.Qd4 is prudent, since he now threatens to play 9...fxe5 without having to face any penalty from 9...Qh4+. Black therefore has no choice but to go ahead and try his counterattack as planned: 8...Qh4+ 9.g3 Qh6 (still trying to save the Knight via a pin) 10.Nc3 (pin released!) 10...exd5 11.fxe5, and now Black sees that White has not been taken in by his trappy counterplay, and can resign in good conscience. But he did at least make an honest try to save his game.
Finally, I should note here that one additional motive for Chernev to end this game score after White's seventh move was quite possibly a Procrustean one, since this game is listed in his 1955 compilation <the 1000 Best Short Games of Chess> as one of a few "Games Won By Moving Pawns Only." Not only that, but he adds in an introductory note to this particular game the curious "fact" that "White moved only Pawns, and Black moved only Knights." Neither of these statements would hold good if the full score were given. Now I am not trying to suggest any disingenuousness on Chernev's part; his earlier work <Winning Chess Traps> (1946) showed exactly the same number of moves for this game, which was entry number 145 of the 300 traps in that book, and there was no "Believe it or Not" spin on that earlier book. Though we'll never know for certain, my guess is that Chernev was following practice that had already been established with regard to this game, and that it didn't occur to him or anyone else until 1978 to look into what might have happened if White had played 8.fxe5 in response to 7...e6.