General DiscussionAbuse or what is this?

I have played twice with the guys on huskar and lycan. Here is the link https://www.dotabuff.com/matches/3712057118. When I was playing with them they had really high win rate on those heroes. When I played with them for the second time I became curious how they again got together in the same team. I checked their dotabuffs and it seems like they are playing party, however in the game I didn't see some kind of connection for parties. Moreover, I have strict solo matchmaking. What is happening?