Well, you might have gotten lucky, I've seen some that fire up with only a hint of misfire (slightly bent valve) or some with several misfires (several bent valves).

Since it happened at low rpm, I would think you might have been on the lucky side of this.

I'd think about just going to the local parts store and get a timing belt (like $25 or so) and putting just the belt on and firing it up.

You can start the engine with everything off the front, no belts or whatnot, but only for about a minute before it's no longer a good idea. Long enough to see if you've got a misfire or not.

Beats spending a ton of dough just to find out you need some headwork.