How do owl and rdfs property domain range work?

I am trying to understand the semantics of rdfs domain and range. Because I am from an object oriented background, I am struggling to understand the semantics and how to validate data against the rdfs statements.

Here is a sample file in turtle format:

PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
prefix tmpl: <http://template.example.com/>
prefix data: <http://data.example.com/>

    tmpl:Thing a owl:Class.
    tmpl:Employment rdfs:subClassOf tmpl:TemporalThing.
    tmpl:Party rdfs:subClassOf tmpl:Thing.
    tmpl:Individual rdfs:subClassOf tmpl:Party.
    tmpl:Organisation rdfs:subClassOf tmpl:Party.
    tmpl:LimitedLiabilityCompany rdfs:subClassOf tmpl:Organisation.
    tmpl:hasCurrentEmployer a owl:ObjectProperty;
        rdfs:domain tmpl:Party;
        rdfs:range tmpl:Party.
    data:Simon a tmpl:Individual;
        skos:prefLabel "Simon S".
    data:PtyLtd a tmpl:LimitedLiabilityCompany.
    data:Simon tmpl:hasCurrentEmployer data:PtyLtd.

    tmpl:Animal a owl:Thing.
    data:Beans a tmpl:Animal.
    data:Simon tmpl:hasCurrentEmployer data:Beans.

I am using GRAPHDB as my test environment. I would expect the last statement to fail with some sort of message because 'Beans' is an 'Animal' which is not a 'Party'.

Yet, GRAPHDB just accepts the statement.

Any ideas?

EDIT

Based on Stanislav's comment below: While An inference engine might not have a problem with this, we can use the domain and range for error checking in an application.

As said in the comments, you misunderstood the semantics of domain and range.