I can't imagine one of our attack subs maneuvering with the periscope surfaced - at least not so that it would be easily observed. As for intercepting of electronic data or communications, we have plenty of airborne assets in the area for that, and for visual information our current satellite coverage of that part of Earth is probably near saturation.
Since the sub was detected visually through use of the periscope I would think French as well.
I'm well aware that espionage takes place among allies as well as enemies. When it takes place among allies, it isn't discussed through the media in an accusatory manner. Something about biting the hand that feeds you.
The USS Narwhal, and a few raven conversions of the old Sturgeon class attack boats did electronic eavesdropping on the Soviet union.
They had to maneuver at periscope depth while exposing what basically looked like a fiberglass covered CB antenna to catch signals.
Not fun I hear, but that's the basics on how it is done.
Airborne assets can be detected out further than a whip aerial can be detected, and any electronic chatter can be diverted or cessated before any useful intel can be garnered.
(This is stuff some poor patient Navy type explained to me once. Or at least TRIED to explain.)
RE: "Since the sub was detected visually through use of the periscope I would think French as well."
I wouldn't be too quick to believe that method of detection. I suspect it was disinformation to conceal the real method. We have listening devices scattered all over the ocean floors, and I'll bet that Israel has devices scattered all over their territorial waters.