Markdown rendered with span class="err" (BB-13628)

Hi, there are a couple of places where source code in my Markdown gets rendered with <span class="err"> surrounding it. For example:

Test

POST /api/a
GET /api/b
POST /api/c
GET /api/d
PUT /api/e
POST /api/f
DELETE /api/g

And the same block as a snippet.

What's causing the red highlighting? I'm pretty sure this is properly formatted Markdown.