Steps to reproduce:
1. Create a new material
2. Set materials "Rendering Mode" to transperant
3. Change standard shader to any other (e.g. Unlit/Color)
4. Turn on "Debug mode" for inspector
5. Reset material from the inspector

Actual result: Values under "String Tag Map", notably the Render Type, has not been reset, while other values have been

Expected result: Values get reset to the default values and "String Tag Map" becomes of size 0

Tested and reproduced:
Windows 10
Unity 5.1.4f1, 5.2.4p1, 5.3.3f1, 5.4.0b7

Note: The values that do not get reset, do change if you change them from inspector in normal mode.