The anger was about the situation that led to the goal, a melee that Mjällby got a free kick on.
A long play and post reached Löfquist who stepped forward and nodded in 3-2.
The victory means that Mjällby climbs from tenth to eighth place.
Helsingborg remains in the qualifiers.
- It is very sad to lose a match like this when we create incredible situations.
But this is football, says Helsingborg's Armin Gigovic to Dplay.
It was just over two months ago that Helsingborg's Danish goalkeeper Anders Lindegaard last played a match.
But now he is injury-free and was back between the posts in the away meeting with Mjällby.
Coach Olof Mellberg said before the match that it was important for the team that the goalkeeper, a leader in the team, was back.
Heeled goals
But already in the eleventh minute he was put on a test that he failed. Mjällby's Moses Ogbo hit a post that midfielder Jesper Löfgren heeled in.
- It was a small, small touch, says Löfgren about his first Allsvenskan goal, to Dplay.
Helsingborg, who despite a fine autumn continue to fight in the lower region of the table (qualifying spot), equalized with ten minutes left of the half.
Brandur Hendriksson Olsen spliced the ball at the far post after Adam Eriksson's post.
The goal gave energy
Five minutes into the second half, Helsingborg's top scorer Anthony van den Hurk made it 2-1 after Kebba Ceesay nodded the ball forward.
That was van den Hurks' eighth goal this year.
Besard Sabovic struck a 30 meter free kick home 72 minutes into the match.
- Then we got a little more energy.
It was an even match but I think we lead the match a little more when it is decided, says Löfquist.