Elaborate these "serious safety issues" for us please
You are releasing the retention device with the same device that activates the trigger.
The Serpa is a disaster that HAS happened.
Here is an example on video:
http://www.youtube.com/watch?v=zYvAxLX6OzE
As for other examples, I had a student who had done the same during an IED attack in the gulf several years ago.
I also saw a student fire a simunition round into his own leg in similar fashion during active shooter training using a SERPA.
As a previous poster noted, I have seen the SERPA fail to disengage the pistol when dirt and tiny rocks get in the mechanism during a grouned struggle.
There are other good retention holsters out there.
Michael Brown