Answer:
The final statement is true
Explanation:
What happened is that Leonard's organism was not "expecting" the drug. Leonard had most likely associated his apartment with the consumption of heroin., and had developed a tolerance from continued use. However, tolerance occurs because the apartment signals to the body that heroin consumption is coming, thus preparing the body for it. When using at a new place, Leonard didn't have the cues in his apartment to signal to his body he was about to use heroin. Thus, tolerance did not kick in and the "regular" dose became too high for his unprepared organism, almost causing him to fatally overdose.