Agree that benzo + alcohol is a very bad mix indeed.
I do however disagree with this characterization of the state of "blackout". People are no more prone to rampaging, aggressive behavior or violence when in a state of blackout than they are any other time. And they do know what they are doing in the moment. I mean, as well as one can while under the influence anyway.
A "blackout" is the result of an incomplete or absent memory transfer from short term memory to long term memory. A person in a blackout state has perfectly functioning short term memory - you can, for instance, watch a movie and follow along just fine or participate in a conversation. You are present in the moment, likely behaving much as you normally do. The problem that arises in a drug or alcohol impaired state is that the substance can interrupt the transmission of data (memory) from short term memory to long term memory. The following day you may not remember watching the movie or having a conversation but you were perfectly aware during the event itself.
Benzodiazepines are notorious for this. In fact, it's the reason Versed is deliberately used during outpatient medical procedures. The patient medicated with Versed can cooperate with the procedure and the doctors because they are awake and reasonably alert in the moment, but don't remember a thing about it afterwards (blackout). The formal term is anterograde amnesia.
Benzodiazepines, shown to affect memory, can produce anterograde amnesia (i.e., a loss of memory for events occurring forward in time). Following the ingestion of a benzodiazepine, short-term memory is not affected, but long-term memory is impaired. The memory loss may occur because events are...
pubmed.ncbi.nlm.nih.gov