Character mistake: Horatio writes the symbols for sulfuric acid, H2SO4, on a clear board. Both numbers should be subscripts but he writes the 4 as a coefficient (which precedes the name of the acid but he writes it after), suggesting a lack of basic chemistry knowledge.
Episode #4.4 - S4-E4
Character mistake: A computer screen giving details of the villain of the week contains various spelling and grammatical errors: "Embassey", "Assination" and "Assination of with".
