Is there any occasion in the bible where Jesus explicitly condemned slavery and slave owners for their treatment of slaves? Did he have amply opportunity to condemn it if he so wished?

Watch his for some interesting ideas.

Very biased and misleading video.

Just one example is where it uses Corinthians 5 to say that the NT ordered slaves to obey their masters.
Corinthians 5 isn't about slaves. The Greek word used in the original text is not "skavlos" but is "douloi".
Doulos were not always slaves. Anyone who worked for an employer could be called a douloi as could anyone who had no voting rights. Serfs and paid servants were also known as doulos.

If Jesus was referring to slaves, it's almost certain that the word "skavlos" would have been used.