Well.. At first they may have thought that Simba was going insane(-attacking Scar for no reason-), but then they get angry at Scar for lying to them all those years; and almost forcing them into starvation. Ofcorse; there are some strange things happening in the scene - such as how the lionesses run to attack before the Hyenas jump on SImba. However that can be explained. The Hyenas were growling and slowly getting closer to Simba when he was ordering Scar to tell them the truth. So the lionesses could predict what was going to happen. Plus it didn't really matter wether or not the Hyenas were going to attack Simba, as they would want to attack Scar and the Hyenas anyway after what they heard. So the Lionesses were in shock before and when Simba pounded Scar to the ground; but then when Scar shouted out that he was guilty of Mufasas death, all the lionesses wanted to kill him and the Hyenas.
Wow that's pretty long!

They dont hate simba. Funny concept, eh?... I don't know
WHY they would hate Simba. Maybe angry, but not to the point
of hatrid. XD

^^maya,thats right

or they could have been trying to attack scar but then the
hyenas attacked simba so the lionesses attaced the hyenas
instead of scar

It was like this. The Hyenas attacked Simba. After seeing
The Hyenas attack Simba, The Lionesses attacked The Hyenas.

how would they know that the hyenas where going to attack
him

The Hyenas Attacked Simba. Then the Lionesses attacked The
Hyenas.

They obviously knew the hyenas were going to attack Simba

but the lionesses started attacking first and then the
hyenas

They dont hate simba. Funny concept, eh?... I don't know
WHY they would hate Simba. Maybe angry, but not to the point
of hatrid. XD

what?