Boeing Probe Could Spur Rival Lawsuits  WASHINGTON (Reuters) - A confession by the former No. 2 Air  Force arms buyer that she steered contracts to her future  employer, Boeing Co. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=BA.N target=/stocks/quickinfo/fullquote"&gt;BA.N&lt;/A&gt;, could spur legal challenges to old  contract awards, legal experts said on Monday.