They'll probably be able to revert it but try telling them how it happened lol, they'll just blame you and end support.
Cache...
The problem is you deleted Cache, not Data.
A Value that is necessary to let the Game run most likely won't be in Cache.
Cache is just to make things a bit faster and not have to do the same Calculations over and over again.
But what he (probably) did was break a Value necessary to run the App correctly, not break any Calculations.
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added 4 minutes later
Yes i know it is impossible, but if this one important Value just broke itself not other Values,
Technically (unlikely) he could search for the Value he broke and fix it.
He'd need to know which one from the Pool of 1000000 Values to do that though, which would work, but it's impossible to find your Value in there because its all the same.
In Short: not impossible, but not a chance either