It is unlikely that the seller will 'get away' with avoiding the estate agent commission. If they have signed a contract (and it seems very likely that they have), there is normally a clause to the effect that any person making an offer that leads to eventual sale is assumed to have been introduced by that EA unless specific exclused names of potential buyers are listed in the contract. Unless the seller made it clear to the EA that you were an interested party that had approached the seller prior to the EA engagement and named you, they will be liable to pay commission.
EAs are remarkably efficient at ensuring that they don't lose out on commission.
The reason when the 'named individuals' part most often comes into play is when a seller disengages one agent to appoint another; if there are interested buyers from the first agent who eventually purchase, without such a clause, the seller would end up paying 2 lots of commission - one to each agent.