The only distinction is that personal savings usually do not grow at the same rate, thus the different qualification of risk.
Anyway, your story is enlightening and interesting regardless if it was "impurely" bootstrapped, so apologies if I made it seem as if that was the most important thing.
I would define bootstrapping more on par with autonomous scaling. The criterion pertains to the risk in capitalization. The more the risk is self-owned, the more the "quality" of the bootstrap :)
Profits from another business, in and itself, are technically also from personal savings.
But yeah, maybe our story doesn't subscribe to the purest form of bootstrapping.