That doesn't make any sense, even if they surrendered mistakenly based on the actual military realities, the Dalia Lama is just one man, you can't sum up a people's identity and claim to cultural uniqueness in one.
Not that I think the pre invasion Tibet was some kind of utopia of peaceful monks, it was more akin to religious autocracy, even if it lacked the extreme repressive measures we usually associate with the term.