Oil leak

The other day I brought my wife's car in to Midas because I just bought new tires from them the beginning of the summer and they were wearing on the outside edge of the tires. They said I needed struts. At this time I did not have an oil leak. That night I put the car in the garage so I can look at it the next day after work and by that time there was a huge puddle of oil on the floor. Could they possibly have touched anything to cause the leak or could this be a huge coincidence? It's hard for me to tell exactly where the leak is coming from.