Prevent negative budget after a transfer (pre-post status)

I have a situation where the system allows budget transfers (with insufficient budget) to pre-post using FMBB. The scenario is as follows...

Cur Exp Avail

FundCenterA 100 50 50

FundCenterB 200 25 175

Although only 50 is available in fund center A, the system allows the user to pre-post a transfer for more than 50 (75 for instance) from fund center A to B.

After the initiator creates the pre-post transfer document, approval of the transfer is attempted by a budget analyst, but the document remains in pre-post status and the analyst can't take any further action.

Can preventing this be accomplished through consistency checks causing the initiator to get a hard error? If so, how or why not? If it cannot be done using consistency checks then what are my choices.