Material Design isn’t one single thing, even at Google.
I spent about 5 minutes taking some screenshots of different Google properties and their interpretation of Google Material Design. None of these are “pre-material”. Quick looks:
The new Google Calendar is much better than the original mess. However, they are stretching material in new ways. Notice the blue SAVE button on the top right. Also, the fields have background colors and icons on the left.
Google Inbox (to me) is a nice improvement over GMail. Notice the blue SEND button on the bottom left. Form elements are transparent with gray lines.
The new Google Contacts is very material-y. Notice the form elements and the SAVE button at the bottom right with no box around it.
In Maps, Adding a place is pretty lame. This feels pre-material, but notice the slightly different button at the bottom right.
The sign in is a big NEXT button with material form elements.
The edit home address in maps has a SAVE button on the top to the left of a cancel link. No background box here.
The new Google Analytics is still pretty old. Yuck.
Google keep has a DONE link (not SAVE) with no button box on the bottom right.
I could go on and on. What is the point?
The point is that there is no such thing as perfect Material Design. If you are using it at all, you must realize that even at Google, they are making it up as they go along. They have rough guidelines, but even things as simple as form elements and SAVE buttons are done in a wide variety of ways. The shadows aren’t consistent, the placements aren’t consistent. Nothing is consistent.
If you use Material at all, you are in danger of looking “off guideline” because Material is not a robust enough system to cover every case.
You need to make your design be different enough to claim it is YOUR style. Don’t just ape the material guidelines. Have a style that is unique to your situation and case. One day Material will seem old and dated. Don’t be a slave to the fashion.