The bug

The command syntax help for /scoreboard teams option shows the option names capitalized but the feedback when setting an option or when no or an invalid option value is provided prints the option in lower case.

Note: If the lower case versions are intended it would be good to replace all options and values with lower case and words separated by underscores ones. Otherwise options like seefriendlyinvisibles are kind of hard to read.

How to reproduce

1. Create a scoreboard team

   /scoreboard teams add testTeam
   

2. Have the syntax help shown

   /scoreboard teams option
   

   → You will see for example "seeFriendlyInvisibles"

3. Have the syntax help for this option shown

   /scoreboard teams option testTeam seeFriendlyInvisibles
   

   → You will see that the option is printed in lower case: "seefriendlyinvisibles"