Well, I don't blame Donna, she didn't know the Doctor all that well and I'm sure she'd have been more specific if she'd had more time to consider her ad=vice to him. Still, he did pick a strong, capable woman in Martha. I think the blame lies with the Doctor for not being ,ore honest and open with Martha. Then again, he seldom really opens up to anyone, preferring to hide himself away as much as Jack tends to.They're more alike than the Doctor would be comfortable with!