This was noted also
here. My guess is that the developers don't perceive it as a bug, but simply a choice that allows for more compact display of event details. You can get used to the convention that times with no "a" or "p" following them are am times, and those with a "p" are pm times. I'm not saying I like it that way, but I can see why someone might have made that choice. It does seem to be odd that on the web page display of the calendar, it uses "am" and "pm", and that's the place where you need the most compact representation; the convention of using simply "p" for pm times applies only to the generated PDF.
Questions that can benefit the larger community should be asked in a public forum, not a private message.