Absolutely *NOT*.
This kind of damage is not too rare and has been well described in gun examiners' reports and literature. It has appeared always as the same, and its reason was not what you surmise.
To name it:
Faulty fluid barrel steel with linear inclusions.
(Has also been variously described in this forum over the years, as I can see)
I have seen a best quality Lang SLE double rifle with very similar damage, a massive split well down the barrel (and therefore the pressure curve) but no sign that I could see of the start of a ring bulge that you would expect from an in bore obstruction.
Proofing could and would often detect such flaws, but not always.
I suspect that both might have been caused by using over hard homogeneous bullets, without the give afforded by a lead core.
With 95 % or rather 98 % likelihood, NOT.
Carcano