The information officer that was killed reported on an online gaming site that the Libyan guards were taking pictures of the building they were staying in shortly before the attack - and by those actions knew the attack was coming and feared for their lives.
So yes, the Libyan guards were most definitely involved in attacking the people they were supposed to be protecting.
Just a humble observation, but these security details are what I’d expect out of the Peruvian or Romanian government operations....not the US. I’d question who arranges security within the State Department and if they really have any qualifications.