There were no positives just a one-way route to the away goal after a first half-hour when the side in yellow played keep ball to emulate an Premier League side - and then it burst like a party balloon.
A dubious penalty for the first Albion goal didn't help, but Joka was not in the mood to make excuses.
"Generally we offered Brighton so many easy way to the points. At the beginning we keep the ball and stick to the plan," he said.
"I don't know if it was a penalty or not. But if you can't stop this situation, and make this sort of mistake, it then become set pieces we can not defend.
"We opened all the doors to them."
The head coach has clearly done his homework on the set pieces that have proved to be Fulham's downfall in a season that sees them still not mathematically safe from relegation.
Jokanovic was sorrowfully shaking his head at the third Brighton goal when Albion captain Bruno Salter was left to help himself at the back post.
"This is more than 30 goals this season conceded like this - and now there are three more. In total, that's 237 goals in three years and you can not compete for important things with this way. We have to stop it if you want to be competitive.
"We are not safe with this mentality and we could still could pay an expensive price."