It seems you may have found your answer. Partial metering that you had set would favor exposure of things in the center of the frame - about a 6% spot, a lot wider than spot metering but more focused than Center weighted. That could have caused the e...
No, that should keep the subject properly exposed. If you had been using spot, that may have caused exposure issues. There is another setting you may consider, highlight tone priority. See page 206 of your manual. According to Rawdigger, it affects r...