Missing validation

Code maturity is a critical aspect of high-assurance projects. By implementing checks, we can protect against potential mishaps, reduce the risk of lost funds or frozen protocols, and improve user experience. In addition, adding extra error messages can help clarify the internal mechanisms and reduce potential bugs that future developers might introduce while building on this project.

• keeper_cross_chain_tx_vote_outbound_tx.go#L69: VoteOnObservedOutboundTx --- When fetching the current TSS with k.GetTSS(ctx), the returned found boolean is not checked. Even though it is almost always going to exist, it would still be best to check the boolean and return an error instead of panicking on a nil value.