Comment by SwellJoe

Once you take the stand, you have no control over how long you will be on the stand. The fifth amendment insures you don't have to testify if it will hurt your case...but if you agree to be questioned, both sides get to ask pretty much all the questions they want within the bounds of the law and the patience of the judge.

But, yes, it's clear that him taking the stand was the worst possible thing he could do and he apparently fought loudly and repeatedly with his lawyer over this decision.