Draw the box linking those four related switches on the switch matrix. The phantom switch activation you get at the right slingshot is a short circuit fault at the switch on the opposite corner of the box, in this case the top drop target at switch #1.

HarlemGlobeTrotters_SwitchIssue.png

Check it with your multi-meter.
With the game off, and your multi-meter set to resistance mode (200 Ω scale if your meter isn't auto-scaling) how much resistance do you read across the two wires (white-red to white-green) on that drop target switch?
Do any of those wires measure zero ohms resistance to the drop target cage?

Can you post some clear pictures of that switch including from the other side on so we can clearly see the switch leaf separation, the gaps and how they are stacked in the bakelite.

I wouldn't think so.

Well 0.4 ohms is a short circuit..

I don't see enough detail in the pictures, but you may be missing the isolator between the two diode lugs - i.e. the two diode lugs might be sandwiched against each other in the switch stack causing the short.

I can see in that last picture they are sandwiched together.

Move the lug with the white-red wires onto the other side of the thin isolator where the paper separator is - closely inspect another switch if you need to see how they're properly stacked.

BTW, that white-red wire lug must not be touching any other metal part in that stack.