I think the question of who has the liability comes back to what was printed on the can. If for example, you went to O'Reilly and got a can of oil labeled "Citgo", the product liability would rest on Citgo. But store branded merchandise typically will have O'Reilly's name on it and fine print that says something like "bottled for O'Reilly" with no indication as to who actually produced it. In that case, the manufacturer is simply filling the bottle with whatever O'Reilly asked for and O'Reilly has assumed responsibility for the product. In effect (and possibly explicitly), the production contract between O'Reilly and the producer has transferred the liability to O'Reilly. This case is a little more complicated in that the allegation is that both the producer and the distributors knew the product didn't meet the claimed specification. Evidently there were multiple distributors in this case. If again for example, Tractor Supply had a record of you buying 303 fluid from them, you may have gotten a second notice from them.
There were multiple suits. They were combined into a single case that was handled in Missouri. Some fluid testing done by the MO Department of Agriculture entered into the case.
The products and time frames involved are:
MileMaster 303 3/2 gal. Jan. 23, 2017 Present
MileMaster 303 5 gal. May 25, 2013 Present
MileMaster 303 55 gal. May 25, 2013 Present
H-K 303 3/2 gal. May 25, 2013 April 30, 2016
H-K 303 5 gal. May 25, 2013 March 21, 2019
Orscheln 303 5 gal. Sept. 3, 2014 Aug. 16, 2017
SuperTech 303 5 gal. Feb. 17, 2016 Feb. 10, 2018