I'm not sure what the issue is between you two?

Scripture does not teach pacifism. What it does teach is that God is sovereign (power and authority over all things which He has ordained from all eternity and brings to pass through divine providence). Romans 8:28 IN CONTEXT which is the devastating effects of the Fall upon not just mankind but all creation and how that true believers will suffer both from that corruption but because they are believers but they must realize that ALL THINGS work together for good to those who love God, to them
who are the called according to his purpose. Paul continues and focuses upon the believers' salvation in particular explaining that even their redemption has been predestined/foreordained from eternity, not just in general but each and every step of it from their efficacious calling (by the Spirit, aka: irresistible grace) to their final glorification.
Okay, moving on from God is wholly sovereign to the no less incontrovertible truth that man is wholly responsible for every thought, word and deed through his entire life, from conception to death. We are to conduct ourselves appropriately in all situations which Scripture enumerates in myriad places giving many situations as examples for us to follow. The situation with Stephen would be akin to a Swat team storming your house and forcing you outside where they shoot you on the spot. Like the famous quote from Star Trek... "Resistance is futile!" We are to protect our bodies from harm both from self-infliction and by others and this includes the members of our immediate family and as a good Samaritan our neighbors, etc. Scripture and its application, i.e., wisdom given by the Spirit will dictate how we should conduct ourselves.
This simply means as Paul commands in 2Thess 3:10, e.g., if a man is slothful, lazy, irresponsible and refuses to work, then he should not eat (be given food). We are never told to sit around a dining table, pray and then expect manner from heaven to appear on the table. Yet we are told to ask God to provide from our daily sustenance and thank Him for it. Likewise, in a critical situation where harm or death is probable, we are to act in whatever means is available to protect ourselves from harm.
So, what is it exactly that you are having problems with in regard to this person??