Very dangerous question, so thank you for asking it.

Is the culture based on well defined values and set in stone?

Could that person work solo?

Letting that person go is dangerous as you would not be rewarding great skill sets.

Keeping that person is dangerous as you would threaten your company values (for me, culture is founded on values)

Here is the catch: Keep that person and maintain your company values... and you become a GREAT leader.

I hope you go for GREATNESS.

Again, thank you for asking the question.

Steve