The episode is set in New England, however the fire trucks dispatched to the blaze at the sound engineer's office depart from a Los Angeles County Fire Department station.
While handling Tony Eagle's pre-release of his latest tape, the Hardy boys constantly refer to it as a cassette yet every time the tape itself is shown it is clearly an 8-track cartridge not a cassette.
The story takes place in the boys home state of Massachusetts yet when they are up in the air flying their plane around the topography shown below them is clearly in California.