Maybe it's better to say Christ never observed the old covenant?
At least that's a tiny bit more accurate. But for most Christians (including SDAs) this still translate as Jesus didn't keep Moses OT Law. That's false doctrines that promotes blindness.
This false doctrines then leads us to view OT Laws as non-existent and non-relevant to us and say things of this sort :
I will address, first, your question on Exodus 13:12,13. The context of what is said in those two verses is contained in the entire chapter. Verses 12 and 13 address the fact that God slew all the firstborn of Egypt, man and beast, when He redeemed Israel from the Egyptians. Thus, God required of the Israelites, as a remembrance of what He had done for them, that they sacrifice all of their firstborn beasts to Him as an offering of remembrance and gratitude for their deliverance.
...God allowed them to redeem the more valuable animal as a kindness towards them as the beast of burden was of significantly more financial value than a lamb was to them.
This is an example of not looking at the OT as prophecies. If this person would of been taught that all the OT is prophecy, then maybe he would of looked at why God called the COI donkeys(aka asses) several times in scriptures including Ex 13. I know people might find this insulting, but according to the Lord...we are all a bunch of donkeys(==all of us) that needs to be ALL redeemed with a spotless lamb(==Jesus).
How about repeating & beleiving Jesus own words in Mat 5:18 instead?
AV Mt 5:18
For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.