Cave and Thompson may have fallen into the situation where VT just wasn't able to move quickly due to going all last summer with no assistants to help out on the hustings.
Also, I know many may have shied away from Cave, at least, for fear that he would tie up a big chunk of the 11.7, only to turn pro in the end. Which is exactly what he would have done to VT had they signed him; instead, his 800k deal with the Yankees is LSU's loss to deal with, and VT put its 11.7 to work on guys who are now on campus.
It's hard to draw conclusions from the individual situations of one or two players.