Contradiction with Matthew 6:14
This verse speaks of forgiveness, suggesting that sins are forgiven, whereas Deuteronomy 32:34 implies storing up of iniquities, not immediate reconciliation.
Matthew 6:14: For if ye forgive men their trespasses, your heavenly Father will also forgive you:
Contradiction with Hebrews 8:12
Promises that God remembers sins no more, contradicting Deuteronomy 32:34 where there is a keeping of record.
Hebrews 8:12: For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more.
Contradiction with Isaiah 43:25
Indicates God blots out transgressions for His own sake, while Deuteronomy 32:34 suggests storing them up.
Isaiah 43:25: I, [even] I, [am] he that blotteth out thy transgressions for mine own sake, and will not remember thy sins.