Hi - manxbmd.com has under Marriages:
Year, Surname, Name, Parish/Town, Where Married, Page, Entry, Register, Notes:
1908, McMullin, James, Braddan, Braddan, 1146, 329, COE, Not cross checked.

I didn't find a corresponding entry for Theresa Hinton (that's probably what they meant by "not cross-checked" - missed out from the index?) but you should be able to buy the marriage cert from the Registry with the information you have from this and from the 1911 census, if you wish to do so.

Sue