The Grahams were unable to maintain their ground against the combined forces which they had now to face, and fled towards Glencardine, taking refuge in the Kirk of Monzievaird.

The Killearns had no desire to follow up their success any farther, but at this stage they were joined by Duncan Campbell of Dunstaffnage, who had come across from Argyllshire to avenge the death of his father-in-law, Robert of Monzie, who, along with his two sons, had a short time before been killed by the Lord of Glencardine.
An arrow shot from the church fatally wounded one of Campbell's men, and so enraged were the besiegers at this that they set fire to the heather-thatched building.

Of the one hundred and sixty human beings who are supposed to have been in the church, only one young lad escaped, and this was effected by the help of one of the Killearns, who caught the boy in his arms as he leaped out of the flames.

The Killearns did not go unpunished for their barbarous deed.

Their leader, with several of his chief retainers, was afterwards beheaded at Stirling, and an assessment was imposed on the Killearns for behoof of the wives and children of the Grahams who had perished by their hands.
The Killearn by whose aid the young Graham had been saved was forced to flee to Ireland, but he afterwards returned to Scotland, where he and his attendants were known by the name of "Killearn Eirinich" (or Ernoch), meaning Killearn of Ireland.