[Sonar5]

From the press conference Right NOW.

The guy on the press conference right now just said it is only the third occurence of debris hitting it.

Incorrect. At least Five that I am aware of.

STS-50
STS-86
STS-87
STS-112
STS-107

That is at least 5 debris reports from official sources in my links.

[GovernmentShrinker]

Do you know what tank number was the last one of the LWTs? (I'm assuming no LWTs were produced after the production of SWLTs began -- anyone know if that's a safe assumption?)

[ContemptofCourt]

I did not see the press conference, so I do not know the context of the question asked, but they may be stating the truth....STS-27 also suffered severe tile damage, which they postulated occured on liftoff...however, they could not confirm this.

So it depends on whether the question was if something hit the tiles on liftoff or if there have been instances of foam coming off the ET.