Yes and further on that point DD, Ted seems to hang much if not most of his approach on his view of the 5th and 6th Trumpets. But the thing is, there is no "official" SDA position on the Trumpets. In fact, today's premier official SDA theologians, such as J. Paulien, argue the 5th Trumpet is secular-atheism and not Islam:

https://www.ministrymagazine.org/archive/2012/01/the-seven-trumpets-of-revelation

Ted seems to apply Uriah Smith's original view, that put a lot of emphasis on the 6th Trumpet being the Ottoman Empire, and linked to Dan 11. Yet Smith's approach, which once dominated Adventism, was effectively scraped when the Ottoman Empire collapsed in 1918. 

But assuming the 5th Trumpet is "Islam", yes it could mean Muhammed and all "Muslims" are part of a false, evil religion. Or it could mean Muhammed was genuinely called by God, as a prophet in the mould of Balaam, with a godly mission to punish the apostate Catholic-Byzantium "Christian" empire.