I didn't notice any specific instances of this, but there were some CSS rules that made text bolder. That is fine, unless the reason you are making the text bolder is for emphasis. For instance, it's perfectly fine to use CSS to make text bolder for an h1, h2, etc., but it's not OK to use a CSS rule like .important-info
to mark some text as bold simply because it's important. The reason the second example is not alright is because the screen reader user has no semantic information about the text being important. The accessible way to do it is to use the <strong> or <em> tags.
This is akin to issue http://tracker.moodle.org/browse/MDL-30898, where there weren't any instances found, but the possibility of misuse was there because of existing CSS rules. I included this bug in this meta issue simply for completeness because it was part of the original report.