Right, lets settle this nonsense:
1) Outside of a boxing ring there is no such animal as a "fair fight". If some [censored] demands you fight "fair"- Don't. "Fair" mean a fight in which he/they have an overwelming advantage of some description.
2) There is an old addage that goes: "Twice blest is he who's cause is just but trice blest is he who gets in first" If it goes pear shaped, use it.
3) Any material advantage you can gain over an adversary, use.
4) Point out nicely to your mate that pepperspray is somwhat nicer than the alternatives. After all, most martial art blows, when delivered in ernest are intended to cripple or kill.
You first priority is to survive. Everything else is a secondary consideration. So ignore them.