I seriously doubt that Sea Foam caused that problem.
My son and I own and operate a small engine repair shop and we use around 2 cases of Sea Foam a week and have for years. We have never had anything but good reports and good luck with it.
It is one of the best fuel/oil additives on the market. We even use it to soak/clean some small engine carbs.
I suspect a hole in the float somewhere....or something else but not just from adding a fuel additive....
James 1:22 But be ye doers of the word, and not hearers only, deceiving your own selves. 23 For if any be a hearer of the word, and not a doer, he is like unto a man beholding his natural face in a glass: (KJV)