general problems of the 2012 Toyota Highlander

I was driving on I-35 and has to stop at the shoulder for about 30 seconds to fix something. The shoulder is smooth and newly paved. Then I went on driving again, minutes late, the tire low air indicator was on and a few more minutes later, the left front tire was totally flat. The tire has only 7500 miles on it and was told by Toyota dealer that I need to purchase a new one. And there is no warranty on it since it is from a new car and I did not purchase their extended coverage. I think it is quality of the tire used and I saw tons of same complaints from other Toyota Highlander owners.