Your colleague is a dick for not backing you up.

When I was in retail (Apple Store), we had a saying “Don’t feed the bears”. Meaning if you give in to petulant outbursts, the offender will keep coming back and asking for more.

It’s a word with no proper opposite.

Have you ever heard anyone use the word “feckfull”?

Well, you just did. This being a conversation in English, feckfull is now cromulent.