So he was approved today and they didn't gave him a hard time. The questions they only asked were:
Name of petitioner?
How and when did you guys meet?
When and where did you got married?
How many kids?
When and why did you overstay?
They took a while to check the i-601a waiver if it's real. Once they saw it's real, that's when they said "Congratulations, you're approved." I took the earliest appointment time (06:30am) and he was able to finish at 08:30am.