EDIT

import eu.etaxonomy.cdm.model.occurrence.DerivedUnit;

        if(taxon.getName()==null){

            return;

        }

        Set<DerivedUnit> typeDesignationSpecimens = new HashSet<>();

        this.taxon.getName().getSpecimenTypeDesignations().forEach(designation->typeDesignationSpecimens.add(designation.getTypeSpecimen()));

        //check if any deleted object was a type specimen

        if(result.getUpdatedObjects().stream()

                //filter only DerivedUnits

                .filter(cdmBase->cdmBase.isInstanceOf(DerivedUnit.class))

                //deproxy from CdmBase to DerivedUnit

                .map(unit->HibernateProxyHelper.deproxy(unit, DerivedUnit.class))

                //check for match in type designations

                .anyMatch(unit->typeDesignationSpecimens.contains(unit))){

            EditorUtil.updateEditor(this.input.getTaxonNode(), partService, application);

        }