Not only was DHS surprised by the signing of the order, it was also surprised by the requirement for immediate implementation, found the report.
The ban caused chaos at the airports as travelers were left stranded and government officials scrambled to implement the ban that was issued at 4:43 pm ET on a Friday. Lawsuits soon followed and one week later a federal judge froze the ban nationwide.
While there was widespread reporting of the confusion at the time, the inspector general report provides an official narrative with unprecedented access of the hours and days that unfolded.
The watchdog also found that Homeland Security officials violated court orders in the process of implementation, although the department disagreed with those findings.
The report itself has been the subject to its own controversy. In an unusual letter to Congress then-Inspector General John Roth, wrote in November that he was "troubled" by DHS’ lack of a timely response to the report.
Typically, the inspector general delivers a report to DHS, which replies with its formal response and any concerns over legal or security sensitivities. Those concerns and response are compiled and taken into consideration before a report released to Congress and the public.
The inspector general's office sent its final draft report to DHS on October 6, 2017. However, the department did not provide its comments and redactions until January, "over three months later," wrote Acting Inspector General John V. Kelly in a memorandum.
His retirement "absolutely did not have anything to do with this report," said a spokesperson for the inspector general's office. Roth decided that it was time to retire after 32 years of public service to do other things in his career, according to the spokesperson.
The 106-page report examines how DHS and Customs and Border Protection (CBP) responded in real time to a number of "quickly-emerging challenges" created by Trump's order. Overall, it found a lack of preparedness to implement the ban, driven by an absence of communication from the White House to administration officials.
CBP, which had primary responsibility for implementing the order, had "practically no advance notice" of when the order would be issued and what it would contain, according to the report.
Answers to critical questions necessary for implementation were undefined when the order was issued. And no policies, procedures, and guidance to the field were developed, found the report.
After combing through more than 48,000 documents and interviewing over 160 people, the watchdog also observed that the lack of a public or congressional relations strategy significantly hampered CBP and harmed its public image.
For example, Acting CBP Commissioner Kevin McAleenan told the inspector general's investigators that he was instructed not to communicate with congressional representatives or the media until he had formal guidance approved by DHS and legal counsel.
Meanwhile, protesters, politicians, families and reporters descended on airports across the country as a perception of chaos flourished, according to the report.
The inspector general found that CBP complied with court orders related to travelers that had already arrived in the U.S. Of the 1,976 people subject to the ban that reached the U.S., 90 percent were allowed entry into the country. One hundred seventy-nine were refused entry.
It was the actions taken to prevent travelers from coming to the U.S that the inspector general found "troubling." CBP was "aggressive" in preventing affected travelers from boarding aircraft bound for the U.S. -- a violation of two separate court orders, according to the report.
DHS argues that the report lacks evidence of a court violation and that no court "found noncompliance with their orders." But, the IG points out that no court has performed the sort of review it did, nor has any one court seen the breadth of material the inspector general had access to.
Despite media reports at the time, the inspector general did not substantiate any claims of misconduct on the part of CBP officers. Nor did the report find any indication that officers intentionally subjected travelers to unnecessary lengthy periods of detention.
The executive order didn't just affect CBP. DHS cancelled refugee interviews across the globe, the Coast Guard forced people to remain on boats and more federal law enforcement officers were called in to enhance security.
The report concluded that "it would have been difficult for any organization to perform seamlessly under those circumstances."
What has become known as the first travel ban has subsequently been replaced twice by Trump. All of the orders have been subject to lawsuits. The Supreme Court announced today that it will hear arguments over travel ban 3.0.