Once president Obama signed the National Defense Authorization Act (NDAA) it appears that word went out to all of the Senators and Representatives who voted for it that the bill was fixed and they should write their constituents reassuring them that it the bill no longer authorized the indefinite detention of US citizens inside our borders by the military on presidential order and without due process of law.
So the reassuring emails were sent to all the constituents who had lobbied against the passage of the bill with the military detention provisions included, and a lot of them were pacified by these earnest statements from legislators who likely either did not read or did not understand the totality of the NDAA as it was finally passed. They were convinced that the addition of the statements "Nothing in this section shall be construed to affect existing law or authorities relating to the detention of United States citizens" (1021.e) and "The requirement to detain a person in military custody under this section does not extend to citizens of the United States" (1022.b.1) actually fixed the problems with the bill.
What they failed to understand is that the first statement is meaningless because the authors of the bill and the president believe that they already had the power to detain civilians in military custody without due process even before this bill was passed, and that the second statement still uses the term "requirement" which means that while military detention of US citizens is not required in all cases as it is with foreign citizens, it is still an option if ordered by the president.
All they had to do to actually fix this bill was change the phrase "not required" in the original language to "prohibited" when referring to the military detention of US citizens and all of the complaints would have been satisfied. That they did not do this when every expert had told them it was the simple and obvious solution and that they instead engaged in misdirection and false assurances, demonstrates a cynical attitude towards the intelligence of the outraged public which had been loudly lobbying against this aspect of the NDAA.