miner(dodgytx)opcheck='imlegit' ->RoadchainSWlite -> otherSWlite-> otherSWlite ->otherSWlite -> otherSWlite

roadchain does no checks and on the data and see's the fraudproof opcode 'imlegit'.. and accepts it and relays it on.. now 4 people have dodgy information.. for no reason.. they cant use it but the 2000 people using the SWlite keep passing it on.. all blindly thinking its valid..

miner(dodgytx)opcheck='imlegit' ->frankyFullNode -||BIN||

franky ignores the opcode'imlegit' and checks the real data. see's its really dodgy and deleted it, its not relayed and its business as usual
then waits for a valid block to be solved, checking that and then relaying that only if satisfied the rules are met