Transaction broadcasting inefficiency

After reviewing the Algorand code, I noticed that transactions are broadcasted to other peers using a pub-sub mechanism without immediate validation. Wouldn’t this approach allow someone to send invalid transactions, leading to high bandwidth consumption?

to my knowledge each node does the verification of the incomming transactions, and rejects them if they are not in the scope of its internal state… So if you try to overspend your account, you can send these txs to as many nodes as you wish, but none will not forward this transaction further.