Employment law question.

Surely that depends on what was discussed at the meeting, the nature of the disclosures made, who the disclosures have been made to and why the disclosures have been made?

The employee reflected on their practice with two of their colleagues.

If it's "work stuff" then of course they can. There's no implied confidentiality. 

I don’t see how reflecting on your working practices with your employer can, at first glance,  be regarded as confidential or protected.

If the outcome disclosure is discussed internally in the company and there is no (two way) NDA, then of course. There are no formal limits to internal communication of these things other than not doing it so as to keep employees happy.

Upward in the management structure probably yes. 
Sideways or down probably no. 

Simple answer is yes. 

Thanks all, now sorted.