Now that I think about it, I believe Tarl made a statement several years ago in a stream that he hated injection needles, almost a phobia of them. Your son's observation and remark here makes sense if my dim recollection of something Tarl said is correct.
The little bit of what I read about using smoking as an ingestion method with heroin suggest that it is either done by users who have an aversion to needles (Tarl is this case), or as a method to test a bag's potency to try to minimize the chance of an injection overdose. At any rate, only 6% of users who started with smoking heroin finished that way, they either finally turn to injection to catch a greater high, or they quit cold turkey. So, according to that math, Tarl has a 94% chance of becoming an injection addict if he doesn't stop the heroin smoking soon (if he is smoking heroin)
