Forest and Spurs played out a drab 0-0 draw at the City Ground, leaving the two sides still on the hunt for their first win of the new Premier League season.
Things could have been very different, however, had Neco Williams’ goal been allowed rather than chalked off for a handball.
Williams thought he opened the scoring, capitalising on some terrible Tottenham defending to bundle the ball into the back of the net.
Following a VAR review, however, it was disallowed, a decision that Forest boss Glasner was left furious with.
"It feels we lost two points today because I watched a few situations back and I think the goal must stand," Glasner told BBC Sport.
“It's not clear and obvious. We have a briefing before the season that the VAR threshold should be high again when VAR intervenes, and I think it was not clear and obvious.
"For me, it is a clear penalty when Neco Williams gets fouled because (Mohammed) Kudus doesn't even jump into the ball, and when this situation happens anywhere on the pitch it is always a foul. In these two situations, we were not very lucky.
“Huge fight from both teams and like last year every game is decided by small margins. I think we had them today on our side, but if there is a disallowed goal in such a tight game, we have to take the point."
Forest are still chasing their first Premier League win under Glasner, and are next in action against Aston Villa.