Standard Yahoo scoring in my public leagues doesn't give Balt the TD. However, I'm in a private league where the commish changed one setting in D/ST. There are two different touchdown points settings for D/ST. Standard scoring only uses one of them. We didn't know what the other was, so the commish saw touchdown and set it at 6 pts. Apparently it's for any fumble return touchdowns. We didn't know what the effect would be, but I see that the Ravens TD was 6 in our private league, but not scored in the publics. Check your scoring and see if D/ST has two different 6 pt. touchdowns.
It still doesn't make sense, but at least I think we know where the 6 came from in our league.