Does difference of rounds won/lost affect ELO rating earned/lost?

Three games ago, I ranked down back to DMG. Since then, I lost two games in a row 14-16, 14-16.

Last night I played a cs_office map for fun with friends, we won 16-0 against a team of DMG-MGE and three of us ranked up to LE again.

Have you experienced something similar? Do you think round difference is important in ELO rating calculations even more than individual performance?