There was a bandit leader by the name of Liu Gui-Tang 刘桂堂, (1892–1943), described on Wikipedia (https://en.wikipedia.org/wiki/Liu_Guitang). This Liu is not Liu Guitang the teacher of Wei Shuren. This Liu died in 1943 when Wei Shu-Ren was 19 years old, and it is known that Wei Shuren did not begin learning Tai Chi until 1958 (see: Wei Shu-Ren). For these reasons it is doubtful that Wei Shuren learned anything from the bandit leader.
However, due to the fame of this bandit leader and the relative obscurity of the times and people involved, I am unable to locate any information on Liu Gui-Tang the teacher of Wei Shu-Ren.