TSA thought they had a terrorist

We had my Mom and Dad with us for almost a month and they just left last week. We had a good time with them and the time just seemed to fly by so quickly. We really did not do anything to exciting so I guess they need to come back if they want to do tourist-type things. When I took them to the airport I figured that I should assist them to their gate and so I got a pass to do so especially when they did not want assistance from the airlines. I went through security first, followed by Mom. Dad was changing his shoes to some of those Croc's (or the knock-offs) so he could put his real shoes through the security scanner. Both Mom and I were on the one side as he tried to go through the metal detector with the Croc's on his feet. I did not hear what was said but I know the local TSA thought they had found their latest terrorist. Several agents converged on Dad and one yelled at him "TAKE OFF YOUR SHOES NOW!!". Dad did remove the shoes and he walked slowly and painfully through the metal detector and I could tell his feet hurt with each step. After the ordeal the TSA person in charge told me Dad had refused to remove his shoes. I told her that he figured that he already had removed the shoes as they were still on the belt. After some discussion we determined there were some communication issues and in the future all he needs to say is that he cannot walk without his shoes and they will scan them after he passes through the scanner.