There exists the current requirement for specifically training aircrew to follow TCAS RA when in receipt of conflicting ATC instructions, precisely because the frequency of these kind of contradictory directions is significant in ALL busy controlled airspace - before anyone asserts that it is a symptom of general poor ATC standards.
Research has shown that ATCOs mentally sort traffic into two types - those requiring constant monitoring and those who are 'procedurally' separated (as in our case here). When something happens to demand the ATCOs attention to traffic which was considered previously 'separated' then the instinctive reaction to try and either reassert the original instruction (perhaps in denial of a deteriorating situation due to the stress of an impending conflict) or 'rescue' the situation (since despite TCAS now removing the ATCO from the loop the sense of responsibility he/she feels for the traffic is not diminished) it takes considerable mental effort to sit idly by whilst aircraft on your screen are busy doing their own thing in close proximity to one another.
I have seen the same thing many times in tapes of incidents in UK airspace as well: and believe me, the controllers I have trained with here are well aware of their responsibilities when aircraft are in receipt of an RA - it's just often easier said than done, particularly when under unexpected stress.
So don't let's be too quick to criticise the ATCO involved, unless he/she persisted in issuing contradictory instructions - just all take this as a stark lesson in the very real benefit of training for this situation beforehand.