What's wrong here, I think, is that the choice of using `short_description` is intermingled with the use of the `strip_html` parameter. 
Basically, it should be something like this:
```
if event.short_description:
    text = event.short_description
else:
    # fallback 
    text = event.description
if strip_html:
    text = ...beautifulsoup magic...
return text
```