Help re: discrepancy of my parents marriage certificate

Hello! As of now, I'm here in Philippines to process my son's FRV. One of the requirement is the marriage certificate of my parents. The problem is, the date of their marriage is different from my birth certificate. I forgot to mention this earlier this morning in German Embassy when I passed my documents. But, I included there a discrepancy letter from a lawyer. Do you think it would be enough? I'm scared that they will ask me to correct this especially it will take 6 months. And I'm already here for 2 months waiting for the visa because I don't want to leave without taking my son to Germany. Thank you!

Why is a marriage certificate of his grandparents needed for a visa for your son? I have never heard of this!
In any case, if you submitted a letter by a lawyer explaining the error (and, hopefully, clarifying which of the two dates is correct), then the embassy might accept it.
If not, you need to get a corrected document.

They want to recheck my documents since I came from Dubai to Germany and didnt went under c.i here. They wanted to authenticate the certificates themselves.