That's not cool, water in the oil right from a new bucket. Glad to hear the store cut you a refund and the tractor did not get operated. I have not used 'chain store' oils because of stories like this.
I have always used chevron THF 1000 in my tractors. I can buy a new sealed bucket or have a bucket refilled at my local distributor.
So do I, in either a 55 or in 5's for makeup oil. Same with my Rotella T6. 55's or in 1 gallon jugs (when on sale as I'm always looking to buy for less). When the T6 is on sale I only buy it in sealed cartons and I'll pour it in the partial 55's. I've never had 'compromised' oil. I NEVER buy any cheap TSC Traveller crap, ever. and I always chek yo make sure the twist cap seal is intact. I gusee you could get a jug of oil that some clown drained and replaced with used oil. Anuthing is possible today with people that are less that upstanding but I've nevr had that experience and I alsways observe what I'm pouring out anyway.
My 55's of Chevron are in metal drums with wire sealed bungs. Same with the T6. The per gallon price is much better than buying smaller quantities and I buy them from my local jobber anyway.
My philosophy is, if the factory seals aren't present, I don't want it.
Certainly not buying Amsoil stuff anyway. Too expensive.
Spruce Deere... I discovered that NAPA carries the hard to get Chevron THC a while ago and they offer it in ones, 5's and 55 gallon drums as well and they will drop ship it to your location (so long as yopu can unload it) via commercial carrier.
Get my grease in 15 gallon open head (but sealed) drums as well and I bulk load my lever grease guns from the air greaser. Been using Mobil synthetic grease lately as the cost of the Lubrication Engineers synthetic grease has went through the roof. Still paying around 1000 bucks for a 150 pound (15 gallon) open headed drum, but a 150 pound drum lasts me about 2 years.
I'm sure I could get bogus oil, anyone can, but so far, I've not had that issue but again, I don't buy cheap TSC Traveller junk in the first place.
As with most things in life, you get what you pay for....