While reading BIP 65 it says that op_checklocktimeverify can be used to create provably spendable outputs by anyone. How is this possible?
Start by reading the whole sentence:
CHECKLOCKTIMEVERIFY can be used to create outputs that are provably spendable by anyone (thus to mining fees assuming miners behave optimally and rationally) but only at a time sufficiently far into the future that large miners can't profitably sell the sacrifices at a discount.
In other words, CLTV is used to delay when an output can be spent, not to make it provably spendable by anyone. The latter is trivial: just don't have any signature checking operations in a script.