Butcher's side appeared to be set to record a memorable victory over the Steelmen on Saturday as goals from Jordan Forster, Michael Nelson and Paul Heffernan overturned first-half strikes from John Sutton and Lionel Ainsworth.
But Sutton's stoppage-time header earned the visitors a share of the spoils in an enthralling Scottish Premiership encounter.
Butcher said: "It's very sore, we're very disappointed.
"It was a tremendous comeback, great character, that's been spoilt by an unbelievably soft ball.
"We've had umpteen chances to clear the ball and we're going to work all this week on throw-ins, for and against, and clearances because it was schoolboy defending. I'm bitterly disappointed we can't defend a throw-in.
"It was a bizarre game and I think that sums up our season, Jekyll and Hyde."
Motherwell boss Stuart McCall had mixed feelings about the result after seeing his team lose a two-goal lead after the interval.
McCall said: "If you said after 30 minutes we were going to get a point, I would have been really disappointed.
"After 85 minutes, if you said we were going to get a point I would have been delighted. I think Hibs started well and got a lot of set plays in the box - but we scored two fantastic goals.
"If we had not lost the goal before half-time, we could have gone on to control it better but it gives them a lift and at 2-1, they've nothing to lose."