Manchester united actually seem to look like they have got a pattern with which they do use against Liverpool such that even in their worse form they still find it really difficult loosing to Liverpool but then it still doesn't take away the fact that Liverpool has been more productive than Manchester united this season, with their results and their performance they have been able to achieve better results than Manchester united.

Especially at A field, Liverpool usually to exhibit better strength than Manchester united would and ofcourse you don't expect they will be playing in a mediocre way from home so they most of perform as they should even if they don't get to win too often but then with Manchester united it's always been really different with how much they are usually able to achieve at once, nevertheless Manchester united still isn't looking any better in their form because they were able to win Liverpool they just always have this strong resistance for Liverpool but are unable to maintain it with other tough premier league teams.

Last season when Manchester united was actually in a much better form, they couldn't win Liverpool so I doubt if this like you did said is their best time to probably get the best results against Liverpool as they are even in a poor form when compared to that which they were in last season but then just like we do know it's football and we should expect anything at any point of which if it does happen we could consider as a normal football happenings.