Guys Houston does not have the cap space to make this trade. They have only $592,897 cap space after their trade with Orlando.
I know you submitted this trade before I made the changes on the database, but the trade with Orlando had been passed before you posted this deal and I think that should mean there's a deadline that's passed, although it's never been specifically encountered to be posted in the Rules before.
I would refer to Free Agency for precedence on this matter. In Off Season Free Agency a GM may make offers to multiple players, but if a player signs with their team and there isn't enough cap space after that signing to make another, then the signing is invalid.
1). If we used the same rationale with trading then, if both these trades were posted simultaneously and the Houston-Orlando trade was accepted before this one, then this trade would still be invalid.
2). If we relax the rationale, as may seem sensible, then I think it would be to say that if a trade has received enough votes to be accepted then the trade has, at that point, already passed, even though the database has not been updated, and so posting a trade such as this one after that point would be invalid.
Personally I'm in favour of Option 1. A GM may submit multiple trades, but if the first trade to be accepted brings their team over the cap then the other trade is invalid. The GM should know their salary cap situation and not simultaneously make trades that will take them over the cap, unless they're prepared for disappointment with one of those trades.
The Houston-Orlando trade received enough Accepts when Walt Frazier gave the third acceptance at Nov 5, 2013, 4:54am (GMT). This trade was posted at Nov 6, 2:05am (GMT), so I would say this trade is therefore invalid.