I think he conclude it by analyzing the remaining matches.
I can agree that Liverpool has a higher chance to be the winner because they seem having easier matches.
But Arsenal and Man City look to have the same chance. They still have some big matches, including the match between them (Man City vs Arsenal).
The three teams still have the same chance of winning the EPL title, not just one of them because all three teams also have big matches to play, but Man City still has more matches than Arsenal and Liverpool, namely in the FA Cup so Two teams like Arsenal and Liverpool must make the best use of their time so as not to lose points in every match they face when the Man City players' stamina is drained.
Liverpool has less stronger matches and in few league competitions to play till the end of season, this makes them a potential winner of the EPL also, because the players are fully focused seeing they are just a hand stretch away from clinching the title supposing Arsenal and Manchester city get to drop any points on their way.
I doubt that the other potential winners in the teams of Arsenal and Manchester city won't be as determined Liverpool to win the title, mostly for Arsenal who have tougher matches in the EPL and would be slugging it out alongside Manchester city in the champions league QF stage. Let the matches begin.