While Moses seemed 'sure' that he wanted to defend his fellow Hebrew, he also checked first to make sure no one would see him. Was he ashamed of helping a Hebrew? He not only murdered a man, he also tried to hide the evidence.
Positive: He wanted to help
Negative: Didn't want the Egytians, or anyone, to know what he did.
The next day is interesting: He sees two (2) Hebrews fighting and attempted to reason with them by saying "Why are you hitting your fellow Hebrew?" This shows me that Moses', while being brought up an Egyptian, is a Hebrew and will try to help his fellow man.
When finding out that his actions from the day before did not go unnoticed he bacame afraid. Pharoah found out and Moses fled the scene to Midian.
At this point his character seems pretty much like ours: We sometimes act in haste (not thinking)then try to cover it up, but when we realize we were found out we try to flee the scene, mostly in words by justifying our actions.