While Paul Revere’s actions were not nearly as heroic as they are sometimes made out to be, I do not see how they can be said to have hurt the colonists. Revere did play a part in alerting the colonists to the fact that the British regular army was moving out of Boston. This was presumably somewhat helpful and was certainly not harmful.
In April of 1775, the British commander in Boston received orders to capture Patriot leaders Samuel Adams and John Hancock and to destroy secret stores of arms being amassed in Concord. Revere learned of the plan to arrest the two leaders, but not of the plan to destroy the arms. When the army started moving out of Boston, Revere rode out to Lexington to warn the leaders. On the way, he warned people that the army was on the move. After reaching Lexington, he decided to go on to Concord with two other men. He never actually made it to Concord because he was arrested by a British patrol.
It seems likely that Revere’s actions helped the colonists because they could have helped to prevent the arrest of Adams and Hancock. His actions might also have helped alert the colonists, helping to bring about the Battles of Lexington and Concord. We can say that that helped the colonists by allowing them to do well in those battles. This might have helped the Revolution get started. At any rate, it seems that it would be very hard to say that Revere’s actions actually hurt the colonists.