I pulled the carpet back last night and did not notice any water. Before I took it in the first time there was coolant around the tank mount. Actually the trunk area was completely dry. I may get a better look at it this morining when I am in a better mood and it is light out....
DeliriousGA did this repair and said replacing the hoses and especially the factory clamps was important, and cheap too. Check to see if these were replaced. They can crack and wear too.
it's possible they didn't refill the system properly. if the mechanic didn't warm the engine to open the thermostat and properly burp the lines, it's possible that coolant in the tank simply flowed into an underfilled system.