Barr not just a weasel. He's a lifelong Republican shark who got started in the older Bush's CIA and became a superb legal apologist for whatever the right wing wants to do. If Trump still has the backing of the GOP string-pullers, then Barr is the man to make Mueller's report sing his praises. If Trump has somehow lost that (which seems unlikely), then Barr will use it to (metaphorically) rip his guts out and hang him with them.