Can't you just insist that you be afforded the opportunity to tone out the affected cables, disconnect them and not run the risk?
Yes you do run a risk of damaging things if the existing switch (hub) is equipped for POE.
I'm no fan of CGs (computer geeks) either, but you need to demand to have access to the switch to afford you to make the disconnection. Rest assured that if you don't, when the IT guy's car won't start a month from now, it will be your fault.
