In this teshuva printed right after that of Rav Ovadiah Yosef, Rav Goldberg deals first with the case of Thierry Saada, and then considers several other unnamed victims of the 9/11 terrorist attacks. While Rav Yosef spends a large part of his teshuva considering issues of rov, Rav Goldberg discusses several other aspects of these cases, which I am summarizing below.
1) In discussing the use of the conversation between Mr. Saada and his wife at 8:52 (six minutes after the plane hit the tower), Rav Goldberg notes that we can accept the testimony of the wife on this account, since there is no reason to suspect that she is lying and since we have the independent evidence of phone company records that such a call happened at that time.
2) In terms of knowing for certain that the call was placed from Mr. Saada's office (which, since it was on a cellphone, is not clear from the phone records), Rav Goldberg relies on the chazaka that he went to his office as usual that morning, since there is no reason to believe that he did anything different. He rules that this chazaka outweighs the chazaka that he was last seen alive as well as the chazaka that his wife is a married woman.
At this point in the teshuva, Rav Goldberg notes that one year after the tragedy, Saada's remains were identified via DNA and thus his wife should certainly be permitted to remarry.
3) Rav Goldberg discusses various forms of identification of the body that can be used to confirm that an individual has died. He approves of using dental records, bone samples, and DNA, and is not concerned that there would be an attempt to provide counterfeits. In the case of dental records, he assumes that no dentist would risk his reputation by participating in an attempt to provide false records. In the case of bones, the only way to have one's bones be present at the site of the tragedy would be to have them removed in a hospital and then planted at the site. Of course, this would produce a record of the surgery at the hospital, which would undermine the ruse.
With regard to DNA, Rav Goldberg distinguishes between סימנים and טביעת עין. The former refers to general signs, such as a wound on the head, which the observer notices but cannot describe in precise detail. The latter refers to distinguishing features which are unmistakably belong to a specific individual. As there is a 1-in-10 billion chance that two people will have matching DNA, Rav Goldberg rules that DNA falls into the category of טבעת עין and thus can be used as conclusive evidence.
[Parenthetically, he rejects the objection that states that since we have done collected DNA from all people who ever lived we can therefore not rely on it. Rav Goldberg counters by claiming that this line of thinking would undermine the very concept of rov - how do we assert that most domesticated animals are kosher if we have not seen every single such animal? Obviously, we have to work with that which we know from our experience.]
Rav Goldberg also accepts as good identification personal items that one does not lend out, such as wallets and credit cards.
4) In one case, the man presumed dead was a passenger on one of the planes, and the question in this case is whether or not we should be concerned that he disembarked when the plane stopped in Newark (from Boston). However, since the airline had no record of him disembarking we can assume that he did not, especially since it would be in the best interest of the airline for him to disembark (since that would save them on insurance for the loss of his life). Furthermore, we assume that the airline keeps accurate records, since the damage to their reputation if they would lose a passenger would be substantial.
5) One man who was missing and presumed dead was reported to have been in the building by a woman who was not שומרת תורה ומצוות. Rav Goldberg rules that if we can determine that her report about that man was mentioned as part of her larger description of the events (מסיחה לפי תומה) and not as specific evidence about him, then we can accept her words in lieu of other testimony to place the man in the building at the time of the attack and collapse.