But perhaps that was only a hangover from the morning, when he had been working with the Premiership's elite at England's training camp, for by the end of the match the player-manager seemed resigned to his side's limitations. Afterwards he appeared to welcome the sense of perspective this disappointing result should introduce into Middlesbrough's promotion bandwagon.
Having begun the season with four straight wins, Boro's large and vocal support were convinced that they were destined to mirror neighbouring Newcastle and romp the Endsleigh League's senior division as a prelude to becoming a power in the Premiership.
After seeing their team surrender a lead against a side reduced to 10 men for more than an hour, the 2,000 travelling supporters can report back that things will not be so simple. Though Robson's presence inspires his team-mates and intimidates some opponents it stimulates others, as can the atmosphere engendered by Middlesbrough's fans. After initial uncertainty, during which Middlesbrough could have scored twice inside five minutes, Watford warmed to the occasion and the former non-League international, Andy Hessenthaler, typified their refusal to be overawed as he traded bruises and words with Robson.
Watford became even more motivated after Kevin Miller, their goalkeeper, was sent off in the 23rd minute for bringing down Robson on the edge of the area. Though the tackle was ill-timed rather than malicious there was no question that he should be sent off even if Robson, running on to a searching through pass from Alan Moore in a way that rolled back the memories, was going away from goal at the moment of impact.
Reserve goalkeeper Perry Digweed, sensing the chance to regain his first-team place, was stripping off even before the red card appeared; the unfortunate Dominic Ludden - on his debut - made way. Though Digweed was to make two high-class saves from the raw but promising Jamie Pollock he could do little when, 11 minutes later, Clayton Blackmore drove a poor clearance from Neil Cox's cross into a corner of his net.
Since Middlesbrough had not conceded a goal in five matches that seemed to be that. They clearly believed so for they arrogantly eased back and waited for the whistle, only to be undone when Richard Johnson's 25-yard drive was deflected in off Nigel Pearson 12 minutes into the second period. Though Middlesbrough tried to re-ignite their game the momentum had gone and, surprisingly for a team marshalled by Robson, they quickly decided it was one of those days and settled for a point.
Watford, who had worked astonishingly hard, might even have finished up with all the points. As it was, the manager Glenn Roeder had to settle for 'a moral victory'. They ought to be strong enough to avoid last year's struggles for they have some impressive players in core positions - notably Hessenthaler and Johnson in midfield and central defenders Colin Foster and David Holdsworth. But they also have too many moderate ones and, until rebuilding work at the ground is finished, lack the finance to replace them.
Middlesbrough have loftier ambitions but on this evidence not yet the personnel to achieve them. Though Pearson was commanding elsewhere they were more competent than dominant and if Newcastle's achievements are to be matched so must their approach.
When Kevin Keegan's side began their rise from the equivalent division two years ago they opened the season with 11 victories. Their fifth was at Bristol Rovers, where only a brilliant performance by goalkeeper Tommy Wright enabled them to avoid a heavy defeat. Keegan hailed it as 'as good a performance as I have ever seen - and that includes my Liverpool days'. Nine matches later Wright was replaced by Pavel Srnicek and was last seen with Nottingham Forest reserves. Of the Newcastle side at Twerton Park that day only Barry Venison remains in the team.
The Bolivian striker Jaime Moreno ought to be Robson's next purchase, except that after five weeks his work permit has yet to negotiate the Byzantine workings of the Department of Employment. Perhaps the official responsible is the same one who has gone on holiday while dealing with Leeds' attempt to register the South African, Lucas Redebe. No one else, apparently, can do it.
Middlesbrough suffer few startling deficiences - though the quality of the final ball into the box on Saturday was dreadful - just a general need to upgrade as the chance arises. One player who, for the time being, Robson intends to retain is himself. 'I intend to play the season out, unless Viv Anderson (his assistant) decides to drop me,' he said.
It could happen, for the years have taken their toll and, judging by his tired face, so too have the first months of his new position. But it ought not, for he remains a magnificent player and if the covering tackles were absent on Saturday there was little call for them. Instead he concentrated more on those surging runs.
It was a quiet performance by his standards but that was partially because he was as concerned about the performance of others as his own. As better players arrive, and as he settles into his dual role, Robson the player should become the influence Robson the manager needs him to be.
Goals: Blackmore (34) 0-1; Johnson (57) 1-1.
Watford (4-1-3-2): K Miller; Bazeley, Foster, Holdsworth, Ludden (Digweed, gk, 23); Johnson; Hessenthaler, Ramage, Porter; Moralee, Mooney. Substitutes not used: Nogan, Millen.
Middlesbrough (4-4-2): A Miller; Cox, Pearson, Whyte, Fleming; Blackmore, Pollock, Robson, Moore; Hendrie, Wilkinson. Substitutes not used: Mustoe, Morris, Roberts (gk).
Referee: C Wilkes (Gloucester).