But Safeway has arguably been as much the victim of bad timing and the increasing dominance of the market by Tesco and Asda, as ineffectual strategy. Indeed, many of the strategic changes Criado-Perez has brought in since he joined the group in 1999 have been more successful than many in the market have given him credit for. And although he admits he has "failed" in his remit to keep the multiple independent, he insists morale at head office is "strong" now that the potential flood of departures has been stemmed by a £6m golden handcuffs programme.
Leaning back in his leather chair at Safeway's Hayes headquarters, the urbane Argentinian looks more relaxed than seems quite appropriate for someone whose days at the helm must be numbered.
The bid was no surprise, he shrugs. "We had heard rumours for four years that a takeover was imminent or that somebody would bid for us probably Wal-Mart. At the end of last year, we became very apprehensive it was going to bid although there had not been any formal approach. Then Morrisons approached us."
Since that initial bid, the critics have had a field day belittling the strategy of the UK's fourth biggest grocery multiple. As one analyst sums up the consensus view: "Safeway has had no set strategy. It doesn't stand for anything."
Criado-Perez concedes that Safeway, which was spending 3.5% more than Tesco on its buying programme when he joined, has not been able to compete on scale. But launching into a vigorous defence of its strategy, he adds: "We couldn't become an EDLP player, because you have to compare item against item and you always lose. So we had to compete on a high:low front. In this area a smaller player can move faster and do a lot of things a bigger player cannot, and therefore compete more effectively. It's more opportunistic, more creative and you're always looking for promotions."
At Criado-Perez's instigation, Safeway implemented a strategy based on what he calls its "four pillars", aspiring to be best in availability, fresh food, promotions and customer service.
"Clearly we cannot claim we are the cheapest. We have had more of a spearhead investment than an EDLP investment that you can spread like butter on bread. But I think we are best on availability, and if you look at our promotions, rather than compare item against item, we compare very favourably."
It is no idle boast. The multiple now has 1.5 million or 15% more customers than it had four years ago. But last year, the strategy began to unravel. "Just as the four pillars began to mature and the new store formats kicked in, that was exactly when the whole market basically collapsed," says Criado-Perez bluntly. "Our share price suffered. We really had a bit of a crisis of trust we were going to be able to deliver."
There was growing unrest, too, among the suppliers, who complained Safeway was too aggressive in pricing negotiations and often promised in promotions what it could not deliver. "This is a business," he retorts unapologetically. "When we deal with suppliers there has to be business from both sides. No company is a masochist."
Relations with its 2,000 suppliers are good, he insists, but he admits: "We are very keen negotiators and, increasingly, it becomes a more challenging dialogue. it's our job to prise every penny out of the suppliers. Every single penny comes either from them or the customers. We try to do business ethically, but we also want what is best business for our shareholders."
The pressure on Safeway itself is only going to intensify. Uncertainty over the future has already taken its toll strategically. It has been forced to rein in its refurbishment programme and, admits Criado-Perez: "We cannot do the daring things we like to do. Nothing has been shelved, but we're not doing 100 miles an hour any more more like 60."
Nevertheless, while staff were initially "shocked and confused", morale at head office has improved, he claims, and staff even feel "on a bit of a high."
"When the OFT decided what it needed, we were more comfortable about speaking about the future and were able to put in place retention packages to keep people and give them some peace of mind," he explains. "I think morale is very strong. I know the public would be incredulous, but I have been amazingly supported by my people. The proof of the pudding is, so far we have not had people leaving."
The whole team has worked hard over the past four years to find ways to compete in a market it was "always catching up from behind", he says.
He is unequivocal about who he would prefer to emerge as victor. "It would be a very good thing for us to merge with Morrisons. I have a huge respect for the way Ken Morrison does business. That combination would be a phenomenal force."
It would also counter the emergence of a two-tier market dictated to by "the biggest player Tesco and the strongest player, Asda", he argues. "A Morrisons merger would be good for Safeway, good for Morrisons and good for the market."
And as for Philip Green's request for more financial information, he says he will be happy to oblige as long as the entrepreneur clarifies his intentions.
The odds are changing daily on the likely victor. All that is certain is that the days of Safeway as an independent player are numbered. Under the circumstances, Criado-Perez is surprisingly sanguine about his own fate. "Personally, this has been a new learning curve. It's been a very rewarding experience. I'm extremely proud of the job we've done and wouldn't want to be anywhere else.
"I saw it as my job to keep the group independent and in that I have failed. Clearly we haven't done everything right but if I was asked whether I would do it all again, I'd do every bit of it."