I thought about this and it's the only way to be sure the well casing isn't cracked and oil/gas isn't seeping through. This will not be cement so it shouldn't really damage the well any further. BP claiming the seepage may not be emanating from their well doesn't make sense since the seep was located around 50ft from the BOP (source AP wire)......
Oilfield Glossary: Term 'bullhead'