Adjustment of Status - I-485

I had my interview on 02/14 based on marriage to a USC. Our second anniversary would be on 04/16 and we already got a son that's 6 months old. PD is June 25 2015. We were interviewed separately and since our marriage was real most of our answers match except for two wrong answers. After three weeks we got i130 approval notice. We were dissaponited the IO didn't approve us on the spot though after such a long wait for an interview but I've been thinking so hard and worrying alot could it be because of my terrible mistake at the interview? The IO had asked about my previous marriage and asked who filed for the divorce. I answered my ex wife but on the divorce decree it has my name has the petitioner. The IO told me this and I was surprised myself but I called the lawyer who handled the divorce and he said because I paid him the fee he believed I was the one that petitioned for the divorce but it was actually my ex wife who wanted divorce by all means. This fast was stated in the divorce decree though but my worry is could the IO be thinking I have lied? I've been reading stuff online that say USCIS don't take lying unseriously. That's the only thing that's making me so frustrated and scared about my interview. Still waiting for the approval of my I 485 but I don't know if this one honest mistake would jeopardize it. I will appreciate every advice about my case. Thanks