A DESCRIPTION OF THE PROBLEM :
The documentation for MessageDigest.isEqual claims to do a simple byte compare. However, it does a constant time comparison (in order to prevent side-channel leaks).

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Compares two digests for equality. Does a constant-time byte comparison.
ACTUAL -
Compares two digests for equality. Does a simple byte compare.

URL OF FAULTY DOCUMENTATION :
https://docs.oracle.com/javase/7/docs/api/java/security/MessageDigest.html#isEqual%28byte[],%20byte[]%29