The present participle, same as your English versions, is what you want:

• 50% of the time, fixing one bug in one part of the code can cause other code that uses it to work differently, creating another bug.
  → 50% du temps, corriger un bug (or un bogue) dans une partie d’un programme provoque un changement de comportement d’autres parties qui utilisent la partie corrigée, créant un nouveau bug.
• I stepped on the slug, squishing it.
  → J’ai pilé sur une limace, l’écrabouillant.
• Scar blamed Simba for what had happened, traumatizing Simba.
  → Scar blâma Simba de ce qui était survenu, traumatisant ce dernier.

Two notes:

1) One may want to add “de ce fait” after the present participle. Not mandatory by any mean, but it may add emphasis on the action being accomplished

• créant de ce fait un nouveau bug.
• l’écrabouillant de ce fait.
• traumatisant de ce fait Simba.

2) In the third example, I believe using Simba a second time would usually be considered heavy and inelegant in French, unless we add de ce fait as in note 1. Otherwise, the two mentions are too close together.