Hallo.
I have read BIPs 141-144 about Segregate witness and I have a question about validity of SegWit "witnessed" tx for old (non-upgraded) nodes.
Non-upgraded nodes, however, will not see nor validate the witness data and will consider all witness programs as anyone-can-spend scripts.
So they consider such transactions as valid. But what if someone constructs SegWit-like tx (but without valid SegWit script/witness program). Non-upgraded node (eg. merchant selling goods) would see and accept such transaction as valid (and send goods to customer). But the majority of upgraded network would refuse such tx.
Is there any workaround (besides upgrading node to include segwit and besides waiting for several confirmations for all anyone-can-spend scripts)?