I just had 110 rep removed from me today, for "Serial Upvoting Reversed". I assume a spammer was upvoting just to make me upset tonight? My meta rep is still higher then my site rep, but I'm sure that will change soon... Can a mod weigh in on this?
Not sure what kind of "weigh in" are you looking for, Mods don't have access to voting data, we don't know who voted for whom on what post.
Serial upvotes can come from anyone, not just spammers - perhaps a particular user found your answer very good, and went ahead and upvoted all other posts. That would seem to be your case - though as mentioned, without specific details, we can only guess