instances when the dead man's statute NOT APPLICABLE

1. WHEN the testimony does not refer to a matter which occurred before the death of the deceased but merely to documents (Bordalba v. CA);

2. When the executor is the plaintiff in the case, the defendant is free to testify against the plaintiff (Razon v. IAC)

3. Where the defendant (ESTATE of or person of unsound mind) files a counterclaim against the plaintiff (Sunga-Chan v. Chua)

4. When the person testifying against the defendant is an ORDINARY witness.

WAIVER: When a party cross-examines the witness on matters that occurred during the lifetime of the deceased he waives his right to invoke the dead-man's statute. (Santos v. Santos)