You may notice that the Find method started with a capital letter, yet the overridden methods did not. When SCM was first released as AX 7, new methods were created in the same way as with C# and started with a capital letter. Existing methods were then refactored. There is no direct advice as yet as to whether to capitalize the first letter of a method, although it is my preference as it helps to more easily differentiate between methods and public variables when using IntelliSense. So the reason I choose to do this is for readability and because new methods in SCM were created with the first letter capitalized.
Whichever route you take, it is important to be consistent. When overriding methods or implementing a method from an interface, it is critical. In this case, if you implement a method from an interface and change the casing, this will build without error, but will fail at runtime. You may find strange behavior even when overriding methods if the case is different. This is not just the first letter, of course, so using IntelliSense is a much safer way to override methods.