So he gets a sack and instead of admitting that you were wrong, you say it goes against the rules. All it goes against is your interpretation of the rules.
Clearly is the key word in the rules that you quoted. It leaves it heavily open for interpretation. My argument is that Goff wasn't trying to run, he was trying to escape pressure and he was tripped. It wasn't clear that he was trying to become a runner, only that he was trying to get away from the pressure. Few people who trip directly fall to the ground; they stumble to the ground, and if they are trying to protect the ball, they are going to pull it in close to their body while stumbling to avoid possibly fumbling.
I'll say that I only remember one play similar to this where the QB was ruled to be a runner when he was trying to get out of a sack, and it was later corrected to be a sack. Official scorers understand that sacks are an important statistic for defenders, so they are generally not going to interpret it as the QB clearly becoming a runner unless it's absolutely clear.