Unions, arbitrate with the employee the selection of the investigative firm, have the government labor office choose the firm, there are options. They went and unilaterally chose the guys who plaster on their webpage that their goal is to help businesses. Not a single mention of employees rights or ethics.
Their work is to make problems go away for the companies. I'm sure they are awsome at their job. But certainly I agree there's no win scenario for LTT here, and they are beyond fucked as a company anyways. Like all tech bro media companies, they have no clue what they are doing while they grow exponentially and end up hurting people, intentionally or not, but have too much power and money to ever face any consequences.