Ontologies such as this:

<?xml version="1.0"?>
<rdf:RDF xmlns="http://purl.obolibrary.org/obo/obi/example/proplose.owl#"
xml:base="http://purl.obolibrary.org/obo/obi/example/proplose.owl"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:owl="http://www.w3.org/2002/07/owl#">
<owl:Ontology rdf:about="http://purl.obolibrary.org/obo/obi/example/proplose.owl"/>

<owl:Class rdf:about="http://purl.obolibrary.org/obo/obi/proplose/a">
<rdfs:subClassOf>
<owl:Restriction>
<owl:onProperty rdf:resource="http://purl.obolibrary.org/obo/obi/proplose/p"/>
<owl:someValuesFrom rdf:resource="http://purl.obolibrary.org/obo/obi/proplose/b"/>
</owl:Restriction>
</rdfs:subClassOf>
</owl:Class>
</rdf:RDF>

when parsed in strict mode result in dropped axioms because of undeclared classes. This condition is not notified to the user or accessible in the API. There should be a report of some sort to keep users/programmers in the loop.