Is a second, different, claim on the same matter Res Judicata

Question

If someone sued a third party for an action in respect of "theft" but the claim failed as a contract was found to be in place, would that same person be able to issue a second, subsequent, claim in respect of "breach of contract" against the third party in respect of the same issue?

Answer 1

The subcategory of res judicata that would apply is issue estoppel.

There is a strong view of issue estoppel where in any claim or counterclaim that could have been brought about a fact between two parties in a first suit is estopped from being raised in a subsequent suit. This is the rule from Henderson v. Henderson (1843) 3 Hare 100, 67 ER 313.

There is room for disagreement, but I imagine in the hypothetical you've presented, a breach-of-contract claim could have been pleaded in the alternative, even if in an amendment after seeing the response.