Some of the other goofs/problems I noticed in the
American version

Godzilla attacked the ship at 3:30 AM per Raymond
Burr's narration, but the scene is broad daylight
when the first attack occurs.

Dr Yamane speaks to the Japanese council in
English about Godzilla- since he's in Japan at
a Japanese meeting- why not in Japanese? He
talked Japanese language earlier council meeting.

At customs, an officer tells Steve Martin he'll
be detained for questioning. Later, Martin
narrates everyone on the airplane was brought
in for questioning. Then why didn't the
officer make an annoucement to everyone at
customs about being detained instead of
singling out Martin?

Martin is brought in for questioning at an
officials office, then he's brought across the
hall to the steamship company office? What's
a steamship company HQ doing there? The
way it comes across, there's two doors to the
room- one that Martin and Tomo come in,
and the other that Steamship officials enter.

Martin says he's enroute to Cairo, and makes
a layover to Japan. Layovers for flights are
usually a few hours at most, not a few days.
And he did this so he could have dinner with
an old college friend. Plus he says "I'm a
little rusty with my Japanese."