That may have caused it but from the amount of damage, I don't know. A problem like that wouldn't take 7 years to manifest it's self.
It's probably time for me to remind everybody about an issue that almost every ZTR and most walkbehinds have. At 7 years on this Scag mower I'd have to venture an educated guess that this is what happened.
I've posted warnings about this particular part before. This is something that should actually be mentioned in big bold letters at the front of every owner's manual for every mower that uses this part, and it's a lot of mowers. The mods may want to sticky this, it's that important.
Scag and many other mowers use a fuel tank grommet where the fuel fitting passes through the side, bottom or where ever of the tank. These are rubber grommets and should be replaced periodically. They will get old and dry out. When they do that they crack and can leak fuel or just plainly fall out. Ferris uses the same grommets but they mount them high on the gas tank which causes a whole different issue but it's not a fuel leakage issue.
Even if this isn't why your mower leaked fuel this message should be seen by everybody so this is a good thread to post it in.
This is what the grommet looks like:
This is a typical installation using this grommet:
This tank actually has 2 of the grommets. One at the top and one at the bottom. Why it has 2 grommets isn't important for the topic of this thread.
If your mower uses these grommets you should replace them every 3 or 4 years. I have a bunch of equipment that uses these grommets, including a gas powered generator, and all of them have had the grommets replaced recently.
These grommets usually run under $5 a piece so it should never be an excuse not to replace them.
If you have an older mower with these bushings please replace them NOW.