OP - Report this to both DOT (webform on the DOT website and to AA). The sole issue is the passenger's English proficiency, not whether the passenger spoke another language (many people speak two or more). Forget the entire conspiracy issue about whether the AC agent took a bribe or is a buddy of the passenger --- it is completely irrelevant.

This is solely about safety rules and your concern that the passenger did not have a sufficient command of English to deal with crewmember instructions and that this was not properly dealt with at the AC, at the gate or onboard. Stick to that. Nothing more, nothing less.