Originally Posted by
The Beerhunter
you're allowed to ignore tcas in the u.s.????

Remember in the US it would be reasonably common to operate IFR traffic separated from VFR by only 500 ft - and this incident was in Class E so there could be gliders and other non-transponding aircraft - so just whipping the aircraft around without thinking is probably a bad strategy when operating in VMC - particularly as in this case everyone seems to have been operating VFR.