Hearts lost 4-0 at home to Aberdeen, while Boroughmuir Thistle went down 4-1 to runaway leaders Dundee United in SWPL2.
However, there was a big win for Championship South leaders Edinburgh City.
Hayley Lauder's opener, a Lauren Davidson penalty and Kerry Beattie and Priscilla Chinchilla's goals secured City win at Ainslie Park.
McCulloch said: “It wasn’t one of our best performances unfortunately. I expected more from the players, individually and collectively.”
Hibs were 1-0 up at the break at Rangers after Michaela McAlonie got a touch to divert Amy Muir’s superb cross into the net.
But former Hibs forward Lizzie Arnott levelled with a penalty and Jane Ross curled home the winner.
Hibs boss Dean Gibson said: “We deserved more out of the game. I thought we were by far the better side.
“I thought our game plan worked better than theirs did."
Muir picked up an injury and Gibson revealed that Rachael Boyle is also out for a few weeks.
“It’s going to be three or four weeks minimum for Rachel,” Gibson added. “But it is just injury. She is not moving to Saudi Arabia, before the rumours start.”
Elsewhere, Boroughmuir Thistle went down 4-1 to runaway leaders Dundee United in SWPL2.
Edinburgh City remain three points clear at the top of the Championship South after a hard-fought 2-1 win over Renfrew.
Beth Preston’s penalty and Louise Picken’s second-half strike secured the points.