why does opatch lsinventory not reflect what is in opatch_history.txt

hi

I'd much appreciate some help please.

I'm looking into the web logic server -12.2.1.3 - patching history for a client and have been supplied with a copy of opatch_history.txt which shows a patch bundle being applied in April followed by a subsequent patch bundle being applied in December.

But when I look at opatch lsinventory only the latest patch bundle is shown.

I was expecting to see both as an audit trail of patching.

Is this normal behaviour?

Is there any other way of verifying?

Any input would be much appreciated

thanks

Rod