sun.security.validator.PKIXValidator's addResponses method
should add responses to a PKIXRevocationChecker even if revocationEnabled is false. See the specification of PKIXParameters.setRevocationEnabled which says:

"Sophisticated applications should set this flag to false when it is not
practical to use a PKIX service provider's default revocation checking
mechanism or when an alternative revocation checking mechanism is to be
substituted (by also calling the addCertPathChecker or
setCertPathCheckers methods)."

and PKIXRevocationChecker:

"When supplying a revocation checker in this manner, it will be used to
check revocation irrespective of the setting of the RevocationEnabled
flag."