That was very unsporting of Strauss to deny Smith a runner, and it's surprising, since it came a couple of days after strauss did the sporting thing, and call back Angelo Mathews....
I was very disappointed in Strauss's actions. There is a lot of inconsistency with his action.
You can't have England benefitting from getting runners when their batsmen get cramp, and then they turn around and deny an opposing batsman that same privilege.
In 2002, Marcus Trescothick developed cramp in his innings, and was allowed a runner by the Aussie captain:
Australian openers flay England to set up comfortable win | England Cricket News | Cricinfo.com
Before Strauss takes a preachy attitude over having runners for batsmen with cramps, he needs to be very critical of his own who do the same.
In the Lords final of the C&G a couple of years ago, Ian Bell developed cramp while batting with Nick Knight, and used a runner. Is Strauss now going to tell Bell that such behaviour is unacceptable?