Alright, I don't think anyone really misinterpreted anything. we were just arguing the credibility of what Heckran said.
I'm going to give a little recap of the discussion and the evidence that has been provided
The question is what was magus' fate in the unaffected timeline? So far the theorys are...
1. He summons Lavos and lavos Kills him in some fashion. The idea here is that without being interrupted by Crono&co he was able to successful summon Lavos whom then proceeded to kill him. The evidence for this is basically that Guardia stands in all its glory in 1000 a.d. If magus would have continued this war, he most likely would have easily over-run Guardia at some point. This is because Cyrus, their best knight, had already been defeated, along with their second best, Glenn. The masamune was destroyed and from the general setting in Guardia the war looked very grim while the setting down in "mysticville" TM was looking quite promising (in its own undead way). However, you don't experience any of the mystics south of Zenan bridge until you have potentially changed the timeline due to such a thing as chaos theory which will be discussed later. During your second trip their, Zenan bridge is rebuilt and the mystics are then breaking through, possibly lending to the evidence that without Crono&co they would have stormed Guardia pretty quickly after that. However, one thing to consider, every time we see Lavos pop up from his underearth home he generally reeks quite a bit of havoc (blowing up worlds and what not). So if he were to be summoned, one might think the world would have known about it.
2. Magus Summons Lavos, but like with Crono&co is warped to a different time period. This theory can be viewed in two different ways one he summons Lavos and for what ever reason it is Lavos warps him, or that his summon failed in some way and that results in his warp. The same thing that happened in the Crono line is what is being theorized here though. This follows basically the same evidence as the previous theory except for the fact that he does not die. One might think that if Magus was warped to another time period that he would have had an effect on the time period as well (evidence of this was his ability to throw all of 600 ad into chaos in a few years probably 10-20). Since we never notice him, or anything that may have been a result of him in another period, we could probably assume he wasn't warped within the Chrono timeline. If he was though, it would have probably been somewhere in between 65 million bc and 12,000 bc statistically speaking (its a much larger time frame) and logically speaking since the world would have had millions of years to hide the effects of any mischief caused by magus. Although, there is the second magus we encounter in the ds version, could this be that magus? Please keep the time travelers immunity theory in mind.
3. Magus doesn't summon Lavos and either dies of old age (very ultra unlikely) or is sacked by Guardia before he is able to summon Lavos. The idea here is that without the disturbances of Crono&co in the timeline Magus would have laid back and mayhaps prepared more for his fight with Lavos (although why if he thought he could kill Lavos in the Crono timeline but be worried about Crono&co is beyond me). However, many people believe this to be unlikely since Magus has devoted his life to defeating Lavos. Also, it might be added that the disturbances to the original timeline up to Zenan Bridge were quite minor, so the effects that those had on the original were probably minor as well. How would have Guardia even taken his keep, this to me is a very unlikely situation because of the state Guardia is in until Crono comes to the rescue.
So those are basically the theory's, there is little evidence from npc's that talk about the summoning. Most say something to the effect of "If only magus would have summoned the Lavos back in 600ad etc..." The two instances that I found of this in the ds version are from Heckran and from the mystics dancing around the Magus statue in medina square. Other than that I was not able to find any other mentions (and I was pretty thorough about it too). That being said I will still have to go through the SNES version and see what if anything was different.
Also two things to keep in mind is the Time Travelers immunity theory, I believe the compendium has a page on it so I won't go into it, but it relates to magus being warped in the second theory. Second, anything that happened in 600 a.d. after your first visit their may have been compromised. so any npc's from that point on may have had reacted differently had you never went to 600ad. This is partly taken from the idea of chaos theory which a quick google search will inform you about.
If I missed anything or made any mistakes make sure you correct me! and I know you will
edit: Ha, already saw I forgot something. It was also hypothesized that if magus was warped from his summoning of Lavos that his chamber would have been more or less intact. This would have given the illusion that Magus just "took off" and didn't summon Lavos. So the mystics coming upon this would have marked it down in history as him not summoning Lavos.