Eintracht Frankfurt midfielder Kevin-Prince Boateng admitted Bayern Munich should have been awarded a stoppage-time penalty for his foul on Javi Martínez in the DFB-Pokal final.
Ante Rebic scored a brace, netting in the first half and again on the counter-attack with eight minutes remaining after Robert Lewandowski had equalised for Bayern.
VAR had ruled in favour of Rebic for Frankfurt's second goal in the 82nd minute following calls for handball and Kovac's men were fortunate again when referee Felix Zwayer turned down penalty appeals from Bayern players in the fourth minute of stoppage time, with Boateng appearing to foul Martínez in a frantic finish.
Mijat Gacinovic then sealed Frankfurt's fifth cup trophy on the break and Boateng admitted he was fortunate not to be penalised prior to that tournament clinching strike.
"I met him clearly, then the referee must decide," Boateng said. "Honestly, I thought that he was going to award a penalty.
"But we have been lucky that he did not give a penalty. He has to whistle, I'm always honest, that's why I have to say so."
Serbian midfielder Gacinovic added: "I am glad that I have finally scored a goal and such an important one, too."