Repair help

During a repair on an iPhone 6 I was trying to plug the antenna in while the battery was unconnected but I didn’t move the wire away far enough so when I was trying to attach the antenna it started to heat up and spark a tiny fire. I finished the repair anyways and the phone seemed to work fine but after awhile the customer called back saying the digitizer is acting on its own. Is it a possible short on the logicboard or do is it just a LCD that I placed on. The customer hasn’t come back yet but I’m trying to figure out if it’s fixable or not.