Back in AT&T around 2005-2006 a "change of guard" occurred and a very technical team supporting SAP systems lost about half their staff to HP within 3 months. Rumor has it that at&t upper-management had a conversation with HP and a few other people who wanted to go had the door shut in their face.

I know of at least one person who had to quit her job... wait 2 weeks... then HP picked her up. Risky indeed if HP couldn't make good on their promise, but it worked that time.