First, I believe your description in what goes into Results and Discussion aligns with general writing guidelines for scientific writing. However, time to time there are also some articles that clearly violated this "rule" but still reads surprisingly well.
Now, back to your words: "Explain" usually indicates making something more understandable and apparent. While "Interpret" may not necessarily fulfill that function. One way to best gauge what your peers meant would probably be asking them to identify the phrase that "explains" something in the Results section in a sample article, or ask them to write you a couple examples.
Time to time, to "explain" may just mean coaching people how to read a plot, pointing out what is the focus in a table, providing a neutral statement on the direction and magnitude of a statistics, etc. They don't necessarily serve to interpret or provide any qualitative comment, but more to orient readers so that they can glean the most useful information efficiently.
Now, if your peers actually meant "to convey higher-level idea on why or why not a certain finding behaves in a certain way," then I'd vote for putting that in the Discussion section as well.
However, as I said, there are examples written by authors who relaxed this categorization and still managed to keep the paper very clear. I'd consider that skillful rather than rule-defying. But for less experienced writers, my recommendation will be to learn the craft the way as it was suggested by consulting the proper style and writing guides in your field. And later, start to also consider use of space, types of audience, questions that the audience might have when they read up to this line, etc. and adjust accordingly. Is it worthy to mildly break a rule by adding half a line of interpretative statement in the Results section so that the readers can read on without suspense hanging over them? I'd say maybe.
Generally (really, really opinion here), I would rather not to be too dogmatic when discussing scientific writing style with others. Keep an open mind but do know your own field's general "rules." Communicate with them, experiment a bit, it's all fine.
(Yet, one thing that I probably will never mess with is APA style... APA style fandom is strong and I'll steer away from upsetting them.)