Created attachment 185081 [details]
Database document to test the event in a tablecontrol. Open the form and try clicking on the fields with mouse.

Open the attached database.
Open the form.
Click with mouse in some of the text fields.
You have to click twice into a field of a table control. First click will select the field.
A message box appears "Event happens". But in one field of the table control this message box appears twice. This field is set as a field for multi line input.

Now open the macro editor.
SUB Mousebutton(oEvent AS OBJECT)
	DIM stText AS STRING
	DIM oCommand AS OBJECT
	DIM boValue AS BOOLEAN
'	DIM arg()
	DIM stSql AS STRING
	DIM oConnection AS OBJECT
	MsgBox ("Event happens")
END SUB

You could see one of the variables is set as a comment.
Set another of the variables as comment.
Click again of the field of the table control: Event will only happen one time.

This bug appears in 
Version: 7.5.0.3 (X86_64) / LibreOffice Community
Build ID: c21113d003cd3efa8c53188764377a8272d9d6de
CPU threads: 6; OS: Linux 5.3; UI render: default; VCL: kf5 (cairo+xcb)
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: threaded

Bug appears also in LO 7.2.5.2. Couldn't be reproduced in LO 7.2.0.4 (no event ever happen by "Mouse button release" in this version. Couldn't reproduced in LO 6.4.7.2 (event only happens one time). So it is a regression.

Detected with OpenSUSE 15.3 64bit rpm Linux.