Don't have the article, but this thread
has some of the discussion regarding Kasdan's involvement. Relevant discussion starting at post #27, which contains the link Moedred links to above. I think it's possible that an idea developed here about that particular line being written by Kasdan because of the knowledge that Kasdan consulted on the "love dialogue.'
Astonishing that the magazine didn't keep any copies; perhaps they're just not interested in helping. I have managed to track down (concurrent with Moedred) the tidbit that the interview was conducted by Peter Chumo, also rendered as Peter N. Chumo II. The title of the piece was "Matinee Magic: David Koepp and Indiana Jones Enter the Kingdom of the Crystal Skull."
Also, it's a 4 page article. Here
's how it's rendered in an annual film studies bibliography from 2008:
545. Chumo, Peter N, II. "Matinee Magic: David Koepp and Indiana Jones Enter the Kingdom of the Crystal Skull." CS 15.3 (2008): 20-23. On writing the fourth entry in the Indiana Jones franchise.