Momentarily exceeding 20" length

I’ll be inspecting robots at an upcoming event and am looking for clarification on the size rules. There are a number of robots in our area that have throwing arms. At rest the robots fit within the starting position but some momentarily exceed 20" in length as the arms arc upward (through the horizontal) as they make a throw. I’ve assumed that this violates the definition of “expanding” beyond the legal size but would like confirmation.

Thank you in advance.

Yes, you are correct. This is an example of exceeding the expansion limitations.