Enformable (2/28/2012) has a link to the official transcript of NRC's meeting (audio file) on March 12, 2011. In the transcript, I found a mention of GE engineers who were at Fukushima I Nuclear Power Plant when the earthquake and tsunami hit on March 11, 2011.
From the official transcript of teleconferences at NRC on March 12, 2011 (pages 162 and 163):
MR. McDERMOTT: There is one other nugget of information, people might know people.
There were 40 individuals from GE that were actually asked, at this facility, taking part in the refueling of the three units. We understand that out of the 40 people, four were contaminated, but the State Department and GE are working to pull them back to Tokyo and to get them whatever assistance they need to get back to the States.
So the person interviewed by PBS the other day was a GE engineer.
There is no mention of how "four were contaminated" or when. This particular conference call seems to have been in the afternoon of March 12, 2011 in Eastern US Time, so it was after the explosion of Reactor 1.
The fuel had been already in the Reactor Pressure Vessels in Reactors 5 and 6 when the earthquake hit. Reactor 4 was still undergoing the core shroud replacement, and all the fuel bundles were in the Spent Fuel Pool.
I am very curious to know how and when they got contaminated, but the information was not in this particular transcript.