We live in a messy world where regulators often have wide discretion and politically-driven motivations. Guilt or innocence in a matter like this is on a completely different plane from guilt or innocence in a murder trial. Even if we had perfect information about the past, reasonable people could debate endlessly about whether the sum of actions constituted "anti-competitive" behavior (which is banned) rather than just simple competition (which is encouraged, as opposed to, say, collusion).

Since "anti-trust" is bad law, anyone who files complaints about it is "dirty".