You know, it kinda bugged me so before I went to bed I double checked the definition of arrest and I would say it fits in this case... I stand by my previous statement that they were indeed arrested and brought in for questioning (not by choice as you implied in your post).
Source: Merriam-Webster's Dictionary of Law, © 1996 Merriam-Webster, Inc.
Main Entry: 1ar·rest
Pronunciation: &-'rest
Function: noun
Etymology: Middle French arest, from arester to stop, seize, arrest, ultimately from Latin ad to, at + restare to stay
: the restraining and seizure of a person whether or not by physical force by someone acting under authority (as a police officer) in connection with a crime in such a manner that it is reasonable under the circumstances for the person to believe that he or she is not free to leave see also MIRANDA WARNINGS probable cause at CAUSE 2, WARRANT compare STOP
When you wake up, check this out. Here is an article to add to your archives. It is from the Oklahoma Gazette who always goes overboard to be politically correct. As you can tell from their tongue-in-cheek comments in their "Chicken-Fried News", they are not buying the FBI/Boren line:
http://www.okgazette.com/builder/BuilderCFN.asp?DocDate=10/17/2005&Prefix=CFN&PathIn=F:\InetPub\wwwroot\inex008\builder\DocIn&RelPathIn=builder/DocIn&MenuDate=10/17/2005