Could this problem have caused my RCD to trip occasionally?

Cricri

I switched my lights MCB on the non-RCD side by a RCBO. When I switched on the bathroom light, it would trip instantly. When, I took the light fitting off and found:
- the yellow/green cable was connected to the N of the terminal block, while 2 black cables were connected to the earth.
- A screw (most probably holding the fitting in the ceiling) punched one of the black cable.

I trimmed the damaged black cable, and switch black/yellow green in the terminal block, light works fine, and my RCBO doesn't trip anymore. My questions:
1 - Since my RCBO doesn't trip, does it mean for sure that 2 black cables and the yellow/green were indeed inverted?
2 - Could these 2 problems have been the cause of my RCD tripping occasionally prior to fixing these problems, even though the lights MCB was on the non-RCD side? Even if the light was off?

I have to admit that I'm not a sparky and that I'm unable to answer these questions, so any help from a pro would be greatly appreciated.
TIA!