Rovers got off to a flying start with an own goal from David Mirfin after just five minutes. Iain Hume made it 2-0 after 39 minutes and although the Iron hit back through Mark Duffy two minutes later, a Chris Brown strike early in the second half sealed victory for the league leaders.
A scrambled late reply from Karl Hawley was unable to prevent Scunthorpe from slipping to a 10th home defeat of the season
"We have been playing better than this in recent weeks without getting the results," said Laws. "But the goals we conceded were atrocious from our point of view. You cannot give a team like Doncaster a start like that.
"There was no real danger when the ball came into our box for the first goal, but the ball ends up in the back of our net.
Our reaction was to look nervous. We defended poorly, passed the ball poorly and with all the mistakes we were making in the first half, it was inevitable Doncaster would score again.
"We then got ourselves back into the game before half-time and needed to start the second half well - but we concede another early goal and the game is gone.
"The defensive mistakes we made left us with too much to do against a team like Doncaster and, to be honest, I don't think we did well enough to deserve anything from the game.
"We are fighting to avoid relegation but giving goals away like we did does not help our cause. We had been improving defensively, but not today."
A fourth successive defeat leaves Scunthorpe in the bottom four - and Laws admits there is no easy way out.
"Our hands are tied, we have what we have got and we have got to try and lift the players again," he added.