Venerable Ru Jun addresses this question (at the 5:18 min mark)
From the discourse, I get a few points:
- Karma has to be seen from the perspective of Infinite Lives (past, present, future)
- using an analogy of planting crops: you plant bittergourd, then green beans, then apples. When you plant the apple seeds, the bittergourd happens to sprout. You will not reason that you planted apple seeds and got bittergourd instead. You understand that it is because you had planted the bittergourd seeds earlier.
- you should not link causation sequentially.