The most likely scenario to me is that Google did suspend the account, but either this is not the reason, or it was only a minor aspect of the algorithm's decision. People are often bad at figuring out what they did wrong when you send a message explaining exactly what it was, people are hopeless when they get no message at all, which is how these suspensions work.
The assurance that they've used no other apps I put little faith in; I've too often both delivered and received the incorrect "but I'm sure I did nothing else, it had to be this!" claim. We do a lot of things without forming strong memories of them all the time. No offense intended to the original reporter, it's just my experience says that's rarely a highly trustworthy claim, even when trustworthy people make it.
You're exactly right. It's been my experience from community moderation that you can give people an itemized list of things they did that led to a response, and often all they'll take away from reading it is the one item they have a strong emotional reaction to.
The assurance that they've used no other apps I put little faith in; I've too often both delivered and received the incorrect "but I'm sure I did nothing else, it had to be this!" claim. We do a lot of things without forming strong memories of them all the time. No offense intended to the original reporter, it's just my experience says that's rarely a highly trustworthy claim, even when trustworthy people make it.