My View is Ganguly had confidence that Ishanth will play out the overs without any problem.. Think in this way..
ha! comeon, please!
the most important thing at that point was Ganguly had to stay at stumps on day 1.. thats why he gave strike to Ishant Sharma.. Instead of losing Ganguly , losing Ishant sharma is acceptable from Team's point of view...
now thats like running away from battle field in evening thinking u have to fight again tomorrow. when he is on for 122 balls, he wud have better understanding of pitch.
and u cant play if u keep thinking i will get out in next ball thats low self-confidence.