No, No, severntofall, That is not the case. Muhammad was a prophet of Allah just like all other prophets. The other prophets had no angel walking with them telling the people that this was a prophet. same with Jesus and Moses. They did not have any one walking with them yelling to the people that those were the prophets, Same for John the Baptist.
When angel told John the baptist that mary was already pregnant there was nobody there as witness. Allah had been sending messengers for a very long time to all nations of the world to all people. There is no nation which was not given a warner. But we have mostly record of the messengers sent to the children of Abraham.
The prophet will prophesise. Muhammad prophesied that the pagans will be defeated. That came true. He prophesied that the Persians will be defeated by the Romans (Christians) within 3 to 9 years (That was around 625 A.D.). That came true. He prophesied that his religion will overcome all other religions and it will spread world wide. that came true. There are hundreds of Muhammads prophesies which came true in time and even today, miracles/ prophesies of Muhammad are becoming true.
Even today, Allah speaks to the beloved servants of Muhammad, like He used to speak to some non-prophets in the Jews and the Christians.