Danny Graham put the Hornets 1-0 up in the 10th minute before Darius Henderson and Lee Williamson were dismissed in the 28th and 34th minutes respectively. Martin Taylor and Ross Jenkins then netted second-half goals to secure a comfortable win over the relegation battling Blades.
"I've obviously got to be very careful about what I say," said Adams.
"But I've reviewed the footage of the incidents and I think there's a case for both players to feel a little bit harshly treated.
"I think the referee left himself with nowhere to go (for the sending off of Henderson) after the first booking. And then the second one, I will defend Darius here and I'm upset that one of their players [Lee Hodson] has been stretchered off - I hope he's OK, I hope he's well and not seriously injured - but quite clearly Darius is watching the ball and as far as he's concerned, after the header, he thinks it's a goalscoring opportunity and I think he's right."
Speaking of Williamson's sending off, Adams said: "If they're going to send players off for that it's ridiculous. It's a booking. Straight red? Violent conduct? I'm not sure about that."