Jesus said that He had seen Satan fall from heaven:
“And He said to them, "I saw Satan fall like lightning from heaven.” (Lu 10:18 NKJV)
Also, Revelation talks of the dragon no longer having a place in heaven, and the context indicates that the dragon is Satan:
“7 And war broke out in heaven: Michael and his angels fought with the dragon; and the dragon and his angels fought, 8 but they did not prevail, nor was a place found for them in heaven any longer.” (Re 12:7-8 NKJV)
To have a place in heaven to start with, he would have needed to be holy.
Not only that but Satan actually holds an official job in heaven, he is the accuser. That's what Revelation 12 calls him, and what his role in Job 1 and 2 is when he comes before the throne of God, he accuses Job. Right now in something of a Heavenly court, Satan accuses us before God the Father, the prosecutor, and Jesus advocates for us, He is our defense.
Romans 8
33 Who shall lay any thing to the charge of God's elect? It is God that justifieth.
34 Who is he that condemneth? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us.
as I believe Revelation 12's war is yet future because it only gives a short time after that permanent casting out, we're currently being accused, but our Advocate is so much greater than our Accuser.
What I interpret Jesus to be referring to in Luke 10:18 is not what currently happened at that time but Jesus knowing the future, and that the spread of the Gospel was going to cause the fall of Satan. Not that it was a reference to a past or present event.
But I know some people see it as a past event and therefore think all angels that could fall did.
I'm of the mind that that war will take place in the future and angels have the capacity to sin and fall, also Paul says we will judge them.
Michael is the only one we can say for 100% certainty by name know never sins. 2/3 don't, we don't know which by name though. We can say Gabriel most likely doesn't, but it's not 100% in scripture.