Bummer ..
I made the same mistake years ago with a 70mm celestron achro , I used commertial isopropyl alcohol and it ate into the coatings , exactly like you have here ,, So its a TAK ?
.
Hope this helps , you have to find out what he used to clean these optics with .
Sorry to be the one to say ,, but as the old saying goes ....
Dont touch any optics unless you know what you are doing , I learned that the hard way , even tho it was a way cheeper scope .
Good luck.
Brian.