What the statute addresses
DWC describes Labor Code §132a as prohibiting discrimination because a worker filed a claim and protecting co-workers who may testify. Read the statute for operative language.
Build the sequence
Record the claim or testimony, employer knowledge, later employment action, and documents linking them. Distinguish facts from inference.
Do not merge issues
A retaliation theory and the underlying injury claim may involve different procedural questions. Label each notice and deadline rather than putting every dispute in one bucket.
File practice: save the notice, date served, and document that explains the next step. A reference page cannot decide an individual claim.