A senior radio engineer on the original iPhone has talked about the stress the team felt in the days that led up to the announcement of the iPhone in 2007. Andy Grignon had been on the iPhone project since the beginning. Much of his stress came from Steve Jobs' insistence on a live presentation, where most such demonstrations are canned in order to avoid problems. Grigon was in charge of all of the iPhone's radios, and if they had any problems in the first public demonstration of the iPhone, Jobs would have blamed him, according to the New York Times:
Cellphones do innumerable useful things for us today, but at their most basic, they are fancy two-way radios. Grignon was in charge of the equipment that allowed the phone to be a phone. If the device didn’t make calls, or didn’t connect with Bluetooth headsets or Wi-Fi setups, Grignon had to answer for it. As one of the iPhone’s earliest engineers, he’d dedicated two and a half years of his life — often seven days a week — to the project.
The run-up to the event saw Apple completely take over the Moscone Center, with extra security hired to look after the iPhone prototypes 24/7. Jobs rehearsed his presentation for five days, and each day brought a new iPhone malfunction, from dropped calls to random freezes to complete shutdowns. On the day of the unveiling, Grignon brought a flask of Scotch to share between the engineers. Every engineer would take a shot after the portion of the demo that they were responsible for had worked. By the end of the presentation, the Scotch was gone, and the first public presentation of the iPhone had been a complete success.
Grignon later left Apple to become a part of the webOS team, moving on from there to found Quake Labs, a software startup.
Source: The New York Times