Stop showing off
Back when the A.I. had invaded the Inn, Lex had taken an attack from an immortal head on, and survived. It was an experience he was not eager to repeat, for every bone in his body had been crushed almost into fine powder. Moreover, the only reason he survived was because the robot had lacked something fundamental that other immortals had, which made it weaker.
So, although Lex of course needed recognition for the event, one could also say a lot of luck was at play. If the robot had not been fundamentally weaker, if the force of the attack had not been channeled into the ground through his feet, and if Impervious hand had somehow not taken control of the robots soul, there was a good chance Lex would have died, or at least been seriously injured beyond what he had been already.