The 34-year-old was bitterly frustrated by the failure of Jurgen Klopp's men to find a way past Ralf Fahrmann, meaning Die Schwarzgelben remain just a point ahead of their rivals
Die Schwarzgelben had the better of an exciting encounter but were unable to find a way past an inspired Ralf Fahrmann in the vistiors' goal.
Consequently, Dortmund remain just a point clear of their great rivals in the battle for second place in the Bundesliga.
"We are disappointed that we did not win," Kehl told Sky. "Schalke were lucky "
Mats Hummels also felt that BVB were desperately unfortunate not to come away with all three points, but he was at least able to take great encouragement out of the performance.
"It's a mixture of disappointment and satisfaction, because it was our best home game for a long time," the centre-half pointed out, alluding to recent defeats against Zenit and Borussia Monchengladbach.
Meanwhile, Julian Draxler was delighted that Schalke had managed to keep their destiny in their own hands.
"Everything is still open," the Germany international enthused. "We are separated by only one point.
"This game has not proven decisive for the rest of the season."