"Peter saw the error into which he had fallen, and immediately set about repairing the evil that had been wrought, so far as was in his power. God, who knows the end from the beginning, permitted Peter to reveal this weakness of character in order that the tried apostle might see that there was nothing in himself whereof he might boast. Even the best of men, if left to themselves, will err in judgment. God also saw that in time to come some would be so deluded as to claim for Peter and his pretended successors the exalted prerogatives that belong to God alone. And this record of the apostle's weakness was to remain as a proof of his fallibility and of the fact that he stood in no way above the level of the other apostles. AA 198.1"
"Wherefore let him that thinketh he standeth take heed lest he fall."
Both passages address the idea that even those who seem strong can fall, and that one should be careful not to be prideful. The EGW passage uses Peter's fallibility as an example, while 1 Corinthians 10:12 is a general warning.