To Vigo or not to Vigo? That is the question.

The arguments regarding the maphack haven't been very convincing so far. To be more precise, these are just suspicions, which are definitely not enough for a verdict, considering the presumption of innocence.

How do you propose to catch a player cheating in Heroes of Might and Magic? I'm actually curious =)
There are only two ways: The first, and most obvious, is to catch them red-handed, but this is not feasible, as everyone is at home playing. There are rare exceptions, of course, with some individuals =). And if such an incredible event were to happen again, I even know that Sir Vertalik would say that it wasn't him, that some silly misunderstanding occurred, that he just stepped away for tea, and some boy walked by and probably installed and launched it.
And the second is subjective, based on an assessment of experience, skill, and understanding of the game. Again, in a discipline like Counter-Strike, there have been situations with PRO players, and again, the games were analyzed, their behavior and actions were examined, and a subjective decision was made.
There's no point in writing anything stupid further, as everything is obvious here.

Here's a person playing. They're streaming. They're chatting. And in the chat, they're told, "what if...". Has this happened? Yes, it happens all the time, at least in every third game. What is it? A hint? Well, yes, it's a hint. But as soon as streaming appeared, so did these hints. The situation here is similar.

Again, some nonsense.
Let's take the streams of comrades from sc2tv, like Tvariny, Sticky, Amilu, and so on. Yes, they are given advice, that's true; people turn to them in difficult situations. But there's a catch: it doesn't affect the overall picture of the game. The characteristic construction of units, the principle of scouting the map, the priority of moves, and so on, there are many small details that make the game personal and that cannot be changed by advice from the chat. Any average player has this, and it's not difficult to track the pattern of the game when the players change; it's just a routine task. And, unfortunately for your group, it was this that you were caught doing.