The canonical grammatical roles we all learned in JHS and high school don’t capture all the relationships that people can have to events. “The blob ate Jim” has a clear subject and object with an obvious relationship, but “Jim died on me” is a bit muddier. “On” in this case marks me as somehow a victim of Jim’s dying, and represents a usage of “on” that is rather opaque to learners in that it has no clear metaphorical relationship to the usual meanings of “on” and also depends on a lot of contextual knowledge to make sense. “Jim died on me” implies that Jim’s death negatively affected me in (to my ears) a vaguer way than “Jim died for me” implies that I benefited – “died for me” implies that he knew I would benefit, where as “died on me” doesn’t imply any intention on Jim’s part.
Passives in Japanese have a conventionalized implication of victimhood similar to this usage of “on” in English. One I hear a lot when we play card games with our young students is 「カードが取られた」kaado ga torareta “the card was taken”, which is literally translatable into English as a sentence of equivalent meaning with equivalent structure, although clearly not as common an utterance in English. On the other hand, it is quite common in the same situation to also hear 「俺は取られた」ore wa torareta “I was taken” or just 「とられた」torareta “was taken”. The surface subject of the sentence (“I”) in Japanese is the implied victim of the action, not its object. The same pattern frequently applies in 「言われた」iwareta “was said”, which kids use when a classmate gets the right answer before them or says what they were going to say.
Part of the reason for the flexibility of Japanese passives is that “surface subjects” are not really subjects in the English grammatical sense. It’s fully possible, to give another example drawn from experience, to say 俺はウィスキー ore wa uisukii “As for me, whiskey” which leaves the relationship of 俺 ore and ウィスキー uisukii up to context. One of the common implied relationships between the topic of the sentence and a passivized verb is that the topic (“I” in the above examples, typically marked with は wa) is somehow hurt or damaged by the action whose subject and object are left unsaid.
There is no overarching lesson to be drawn from this, except that this is the origin of some common transfer errors you see in college-level writing. Not every error is a transfer error of course, but when your students have been taught for 6 years that grammar translation is the only skill of value when it comes to English, you can expect to see a lot of them.