Johnson appeared to be level when he beat Lee Grant with a rising right- foot shot but Hart was philosophical about the decision.
"David felt that he was on but these things happen," Hart said after the match.
"It was tight and on another day it would stand but I was happy with the team's performance."
That was the only effort Forest managed on target and Derby only tested Darren Ward once when Chris Riggott headed into his arms in the first minute.
The rest of the game was a typical local derby, high on effort but short on quality and there were few real chances.
The second half saw the Rams put Forest under pressure but central defender Michael Dawson gave another towering performance although the home side did have a great opening with seven minutes left.
A cross from the right was headed down by Izale McLeod but Malcolm Christie blazed the chance over the bar from ten yards.
It was Derby's last opportunity to win the first meeting between the clubs since April 1999 but Forest also had a glimpse of glory in stoppage time.
Marlon Harewood was sent clear by Gareth Williams but his touch let him down and Grant, who was making his full debut, was able to drop on the ball.
Kick-off 20th October 2002 13:05 at Pride Park | |
Referee: Wolstenholme, E. K. | Attendance: 30,547 |
Final Result | |
Derby 0 | Nottm Forest 0 |
Yellow Cards | |
I.Evatt, 14, unsporting behaviour | M.Harewood, 57, unsporting behaviour |
Red Cards | |
Match Squads | |
Derby 0 | Nottm Forest 0 |
1. L.Grant 2. C.Riggott 3. I.Evatt 4. D.Higginbotham 5. L.Hunt 6. A.Bolder 7. A.Murray 8. R.Lee 9. P.Boertien 10. M.Christie 11. I.McLeod | 1. D.Ward 2. M.Louis-Jean 3. D.Walker 4. M.Dawson 5. J.Brennan 6. D.Prutton 7. R.Scimeca 8. E.Bopp 9. E.Jess 10. M.Harewood 11. D.Johnson |
Substitutes | |
12. S.Elliott 13. L.Morris 14. G.Kinkladze(68) 15. A.Oakes 16. G.Twigg | 12. G.Williams(46) 13. B.Roche 14. J.Lester(90) 15. C.Doig 16. J.Hjelde |