If you use a line thickness of 1 in addLineTool with the LineTool.ARROW option, you won't get the arrow drawn correctly. Using 2 is the minimum to get it working. I think this has been a bug for years now. Hopefully, a maintenance release will fix this.
[eSig developer, copy the code used to draw the manual arrow lines to the addLineTool() one. The thickness of 1 option works fine on manual draws.]
[eSig developer, copy the code used to draw the manual arrow lines to the addLineTool() one. The thickness of 1 option works fine on manual draws.]