Not the same structure at all. "Apple betrayed by its own law firm" is passive voice; your example is active voice. Passive voice in English is constructed with "to be" as the conjugated "helping verb" and the past participle of the actual verb. This is also why the law firm must be prefaced with "by"; the actor is not included in passive voice. earlyriser is correct in his proposed insertion of "was".
The equivalent to your example would be, "Law firm betrayed Apple, its client."
The equivalent to your example would be, "Law firm betrayed Apple, its client."