Post- Final Round Interview: What made specific candidates stand out over others?

Worked at two large firms and at both of them there was at some level a scoring system used. This heavily influenced who would get offers but it could be overridden. This mainly had implications for diversity candidates and ones who had networked extensively or were well connected internally or externally (e.g., relative of a client). For diversity or connected prospects, nothing was made explicit and you had to read between the lines. In any case, if someone really wanted you at the company, they could make a case for you and it would be considered. If a senior person vouched for you, as you’d probably expect, no one would challenge them. 
 

In the end, a vast majority of candidates who received offers did well in all their interviews. There were very few people on the margins.

I’ll caveat that my experience was from a few years ago and that hiring practices can be very firm specific. The dynamic could also be different and more subjective with a small headcount target.