So, 7.65 mm isn't a wooly Mammoth gun...
I think we mostly knew that.
The question is, based on what is available - either logistics or legislation - one makes the best selection allowed and acts accordingly.
In my collection, I have two Beretta .32 ACP/7.65mm pistols. One is the well known 1935 (commercial) version and the other is an older design, the 1921 model (as I recall). They both shoot reliably and deliver shots to the point of aim. They are fairly easy to handle and control. Not a bad reputation, all in all.
The attorney may look about for a 'bigger' pistol; a decent .38 Special revolver might be a good choice (there are FMJ wadcutter rounds available in some parts of the world.) Or he may choose to opt for a fire axe in his next encounter. Based on the report, I suggest the gentleman with the 7.65 mm pistol do a bit more marksmanship training. The three shots in the stomach and lower abdomen are not highly recommended.
Still he won the engagement and good for him.