Part of the eZ Find search results is programmatically available using $result['result']['SearchExtras'];

This includes attributes such as example, has_error, facet_fields, interestingTerms, etc
However, the 'highlighting' is present in the result information from SOLR, but there is no attribute implementation for this field.

It should be possible to access highlighting results using $SearchExtras->attribute('highlighting');

This is particularly useful when performing custom searches with the $asObjects parameter set to false, in order to improve performance.
In this case, there will be no highlighting terms available in the actual SearchResults.