With European ambitions in common, Blackburn and Ever-ton might reasonably conclude that a point each from a typically robust confrontation was a just outcome had not Everton suffered through the kind of disallowed goal that illustrates how confusion still reigns over the offside law.
It came five minutes from the end at the breakdown of a Blackburn attack when Everton's goalkeeper Tim Howard, spotting the chance of a counter-attack, punted a long ball into the Blackburn half which was won in the air by the Everton substitute, James Vaughan.
He carried the ball forward, withstood an attempted tackle by Blackburn's goalkeeper Brad Friedel and scooped it across to Andrew Johnson, who went past Zurab Khizanishvili and rolled the ball into the net. With two other defenders close by, Johnson seemed to be onside yet the linesman's flag was raised, suggesting that the striker had been in an offside position before he became active.
That was the way Mark Hughes, the Blackburn manager, interpreted the decision. Yet, according to David Moyes, who had spoken to the referee's assistant, Johnson was deemed to have been offside when he collected Vaughan's pass, in which case the Everton manager's self-restraint when offered the chance to give vent to his annoyance was extraordinary.
"It was onside," Moyes said. "A minimum of two Blackburn players, maybe three, maybe even four, including the goalkeeper, played Andrew on. It was a poor decision but I said after the [Merseyside] derby that we would not criticise referees, that we are going to have to play well enough that we don't rely on decisions. I just hope this one is not crucial."
If he was bemused, then so too was Hughes. "It is just too much of a grey area," he said. "First phase, second phase, is he active, isn't he active – it just makes it difficult for referees and officials and frustrating for managers. Where are we going with it? It is just a crazy rule."
At least the incident created a talking point after a cagy contest in which referee Alan Wiley booked six players.
In the first half, in particular, scoring opportunities were thin on the ground. Roque Santa Cruz, initially alone up front for Blackburn, went close with a header in only the second minute but it was not until the 27th minute that Mikel Arteta managed the first shot from either side.
There was no Everton debut for defender Anthony Gardner, their late deadline-day capture from Tottenham, because of an ankle injury but Moyes's team are coping admirably in any event without Joseph Yobo, who is at the African Cup of Nations with Nigeria.
His stand-in, Phil Jagielka, looks more at home in his centre-back role with each game. He almost made his mark at the other end, just before half-time, his header from an Arteta corner being cleared off the line by David Dunn.
The second half began with both goalkeepers tested, Howard pushing a low, hard shot by David Bentley around his left-hand post, then Friedel denying Manuel Fernandes with a charging block when, one-on-one, the Portugal international should have scored. He almost did a few minutes later when his curling free-kick hit an upright.
Blackburn, better once Benni McCarthy had been sent on to support Santa Cruz, were stronger at the finish. McCarthy looked to have the goal at his mercy following a one-two with his strike partner only for Jagielka to hurry him into a weak finish, then only the flailing fist of Howard kept out Bentley's dangerously swerving free-kick.