No one is addressing the fundamental and baseline question:
(Assuming the valid sale didn’t exist)
If you buy a beer from a random store, what are the odds that 1. *this* beer was 2. *owned* by a 3. *Jew* 4. *on pesach*.
Need all four. I’m not a great mathematics lian but I believe R’ Moshe held that a greater than 50% likelihood of *all four* means that one should be machmir lechatchila on this Safek derabanan.
Who has the burden of proving the math?
Why are people making all assumptions to chumra?
Why are people applying psakim about Jewish stores which definitely owned *this item* of chometz, to distributors?
All this said, ask a Rabbi. But make sure he knows math, doesn’t get affected by peer pressure, and is capable of distinguishing between things that need to be distinguished.