The thing is I've read the "deals" made on the show are not binding. Afterwards, they perform diligence.

On air, they say "I'll fund you for $500k...!" with "...after we vet everything you just pitched." being left for after the cameras are switched off.

There have been lawsuits around this that came to that conclusion. Though I may be misremembering it and am not really feeling like looking it up.