After two or three years of 'casual' BBO and informal U3A-group playing, a few days ago, with much trepidation

It so happened that twice during the evening an opponent revoked. First time, I was drawing the last trump and to my surprise both opponents showed out. My first reaction was to murmur - automatically: "funny - have I mis-counted?" and then I looked over my hand to see if it was mis-sorted (these things happen!). However, the offending opponent, on hearing me, muttered a quick apology and put down his trump, leaving the mis-played card as a penalty card.
Meanwhile my partner (i.e. the TD) had "shushed" me - I suppose he meant I should have kept my mouth shut - and I should! Difficult to remember these things!
Question is: I know that the Laws on revokes are extremely complicated. What would have happened if I'd allowed the revoke to become established? I won the offending trick anyway. I don't really like the idea of benefitting from penalty tricks awarded after an established revoke - however much I'm entitled.
The second time (different opponents), I was again declarer, and this time I knew the opponent was revoking, so I alerted her. Again my partner wasn't too happy, but surely as declarer I'm entitled to ask an opponent if they've revoked?
I'm down to go back to this club next week - and hopefully there'll be no irregularities next time!