LOS ANGELES (AP) _ Prosecutor Marcia Clark was trying to prod Brian ``Kato'' Kaelin's recollection Wednesday when words failed him.

``What time was it when you were at 26th and San Vicente?'' Clark asked Kaelin, seeking the specific time he and O.J. Simpson drove to a McDonald's for hamburgers.

``It was, like, 9:15, 9:18 on the clock of the car _ 9:15 to 9:18. It looked like it was right past the, uh...,'' Kaelin replied.

``OK, was this a digital clock?'' the prosecutor asked patiently.

``No, it was a numbered clock, numerals _ a digital would be that, too, but you know what I'm saying.''

``I do,'' Clark said.

``Analog,'' interjected Superior Court Judge Lance Ito.

``Analog,'' echoed Clark, answering her own question in the end.

So went the struggle for clarity in the testimony of a key prosecution witness to Simpson's movements the night Nicole Brown Simpson and Ronald Goldman were murdered.

Such testimony _ with incomplete thoughts, hesitations and sometimes hazy logic _ poses a challenge to lawyers, legal experts say.

``He seems like a flighty, kinetic, high-strung kind of individual,'' said Robert Pugsley, a Southwestern University law professor. ``Not incredible, but just very childlike in a certain kind of way, very quick, a kind of staccato style, one that requires a lot of lawyering to get answers out of him.''

Indeed, Clark sometimes had to introduce incidental details to clear up Kaelin's convoluted responses, finally rephrasing questions to be answered yes or no.

``Who paid for the food?'' Clark inquired about the hamburger run.

``I, I paid, but O.J. gave 'em the money,'' Kaelin answered.

``Now you had already given him $20, is that right?''

``Yes.''

``So you pulled out another $20 to pay for the food?''

``Yes.''

Stanley Goldman, a Loyola Law School professor and former public defender, said the problem Clark faced initially was the ban on leading questions, but later in the day she was being allowed to resort to the practice.

``I don't know whether the judge was simply letting her get away with it or declared him a hostile witness, in which case you could use leading questions, or the defense decided not to object,'' Goldman said.

The prosecutor's effort did pay off because ``nuggets'' were coming through, Pugsley said.

At the same time, Pugsley does not think the defense will be too tough on Kaelin unless Clark gets something particularly damaging out of the shaggy aspiring actor.

Goldman agreed the defense should go easy on Kaelin, who comes across as likeable and easy to please.

``I would not aggressively cross-examine him,'' he said. ``You know what I would do? I would just try to show him confused.''

Lawyers have to proceed cautiously with such a witness, Goldman suggested.

``Who know's what he's going to say?'' he said. ``I mean, you have absolutely no idea what his next response might be or what his last response meant.''

Pugsley agreed:

``I think to some degree he is inescapably a wild-card witness for both sides, and I think both sides are handling him with caution.''.