I'm 100% positive that, after all modifiers, the elo values were like I described. The only player with lower reliability than normal was my newbie ally. This game we played was one of his first.
Skasi, I think that sounds like a plausible explanation - that regular springie is still using the old balance system, in which low reliability players are given less attention when balancing, which results in complete newbies being ignored in the balance. So springie would see my team's elo as 1775 (only my elo), even though it is around 1500 (average of my elo and the newbie's elo).