There is nothing wrong with making few conversational comments without being aware of the details in a particular paper. This is how scientists talk to each other BTW. If I was at a conference with the authors I'd say something similar to the OP above, then they'd agree or disagree.
^https://scholar.google.com/citations?user=mBN1xwcAAAAJ&hl=en
There are way too many papers to do that for every one that comes out in my field, though, so I've gotten pretty good at skimming a paper quickly and making a snap assessment. I might say I'm aware of or acquainted with said paper, but I'd never say I'd really _read_ it.
So charitably speaking, I'd interpret the top-level commenter (avsteele) as meaning that they've only skimmed the paper and these are off-the-cuff comments, rather than that they haven't looked at the paper at all.