Lousy way to carry a gun. You run and you've a chance of drop kicking it into parts unknown.....you need it quickly and you do the one legged chicken.....Relax and stretch out and your trousers ride up and expose the piece. You sit and again trousers ride up and expose the piece.
From a use perspective the practice is clumsy........from a concealment perspective it's 'iffy'.
As an aside, I once had a detective working for me that 'speed stroked' his j frame and put a 158 gr hp plus p thru his ankle and out his heel! Do as you will, but after three plus decades as a leo I won't.