Flying pilots shuttle is VERY clearly based on mr Bonny's design, however, the description in the video does say that anyone can redesign it freely. It does seem that Flying pilot has edited some parts, like the umbilicals on the ET, the nose of the orbiter and the OMS pods, some resizing... So I don't think this is common thievery, but he should've been more clear about it.
Here is what the original looks like without textures :
View attachment 59570