That's a property of most (all?) lettuces, but here we are with two romaine-related instances in 5 months.

Interestingly enough, bean sprouts are eaten raw, are not (thoroughly) cleaned before eating, and must be, by definition, held at an unsafe temperature to sprout.

They also cause a bunch of foodborne illness. I think it's a pretty clear connection.

I blanch bean sprouts before freezing them for storage and then toss them in something I’m frying or boiling. Seems to work for me.

So you eat them not raw.

I might toss a few onto something I’m having by chance right then but I typically by them in advance of when I need them and don’t want to have them rot in the fridge

Sure, but why not other types of lettuce like red leaf lettuce, green leaf lettuce, iceberg lettuce, or butter lettuce?

Apparently Romaine is grown in exactly two places, one for summer and one for winter.

I believe the word 'regions' would be more appropriate.