For the England no goal, momentum works both ways. England could have been aggressive and played strong after the call, which they did. But they couldn't keep up the pressure. Or, England could have been sad and gave up. The linesman is supposed to be by the last defender. It's not his fault that was 15 yards out when the shot was taken. A call is a call. And also, a re-tied match at half-time would not have worked well for England. They would have nothing to play for.
In the end, Germany played a much stronger game in general, and deserved the win, even though some calls went against England.
Update - Same thing happened in Mexico - Argentina. That was clearly offside, but it would've been a riot if they took away the goal. Bad linesman bad!