The rear window of Guy's car is smashed when the mob attacks it. The next shot is from inside the car, which shows the rear window still intact.
When Guy runs toward Jill as she is leaving the party to keep her from going to Billy, his left hand is covered with blood. When he returns to Billy and puts his hand under Billy's head, there is no blood on his hand.
In the sudden storm, Guy and Jillian get into his car to get out of the rain. In the close reverse shot of Guy, water is clearly leaking heavily into the car through a crack in the door or window. But in the shot from behind the front seat of both the characters, there is no leak.
Shortly after the downpour, Jill's clothing displays differing states of wetness. When she gets out of the car and starts to walk away, the top half and shoulders have dried; after her last goodbye, it is again mostly wet.
The song by Richard Strauss is incorrectly listed in the end credits. It's "Beim Schlafengehen" ("Going to Sleep"), not "September". "September" is another of the "Four Last Songs" from which this one is taken; lyrics to both are by Herman Hesse.
Billy Kwan should have the same type of dwarfism as his father, yet his limbs and body are perfectly normal despite his small size.
Billy's still camera is a Nikon F2 Photomic, which was not released until 1971, while the film takes place in 1965.
The LE TIGRE t-shirts the reporters are wearing did not come until 1977; they were not around in 1965.
The black Chevrolet has left-hand drive. Indonesians generally operate right-hand drive. In that era, American cars were widely available in many parts of the world with right-hand drive. Some USA manufacturers (e.g., Ford Motor Company, GM, Chrysler) did manufacture right-hand drive automobiles in Canada for export to left-hand traffic nations, usually those from the British Commonwealth. In some cases, some nations (e.g., Australia, South Africa, Thailand) did assemble North American-market automobiles in their respective markets (especially with local content manufacture) where import tariffs are imposed.
As Guy is arriving in Jakarta, Billy Kwan's VO says it is June 25th, 1965, but the Time Magazine Guy is clutching as he passes through immigration is the July 30th, 1965 issue with the famous Marc Chagall self-portrait cover.
Kiri te Kanawa's voice is distinctive, but she was an unknown 21 year old in New Zealand, who had not yet made any classical recordings, in 1965 when the film is set.
When Guy drops Jill at the British Embassy, a member of the crew is reflected in the car window.