Reproduction steps:
1. Open the "bug.zip" project
2. Open the "Test" scene
3. Open the "Example.cs" script
4. Make "Pressed" method private and save the script
5. Notice that the method is still assigned to the button onClick method

Actual result: Method is called from onClick event even though it is private
Expected result: onClick event method gets reset and warning is thrown regarding the issue.

Reproduced on: 5.5.0b6, 5.4.1p4, 5.3.6p4, 5.2.5f1