Leavers get less MMR penalty than me

https://preview.redd.it/pxsrol2lhztg1.png?width=1279&format=png&auto=webp&s=421104fbbe67f4e1f6f7c8901c6ca9585c943dc3

Context: Guy (molleja_acida83) left with like 3-4 minutes left in the game, I stayed. Went toe to toe in a 1v2 (the game went into overtime) but still lost oh well. What doesn't make sense is I lose ALMOST DOUBLE MMR than what my leaver teammate got? Why?