Here's why:
* Informal grammar: The sentence lacks proper punctuation and uses contractions ("going to", "we're").
* Slang and informal vocabulary: "Sick" is used in a colloquial sense to mean "ill," "gaffer" is a term specific to film sets, and "take ten" is a film industry phrase for a break.
* Incomplete sentences: The sentence structure is fragmented and lacks a clear subject-verb agreement in some parts ("until we replacements?").
This style of language is common in casual conversations and informal writing, especially within specific communities like film crews. It reflects a sense of familiarity and ease in communication among those who understand the context and jargon.