There are times when big business embarrasses its best friends. Consider two recent incidents. One of them is serious. The other is relatively trivial. Both point unerringly to shortcomings at the level of top management.

Let me take them in reverse order. In 1982 an immigrant from the Philippines, Juana Evelina Resurrecion Robles-Florendo, invested her life savings in a small restaurant in downtown Baltimore. From childhood she had been known as "Sony." Not surprisingly, in all innocence, she named her restaurant "Sony's."Innocence, alas, may carry a high price. Lawyers from the vast Sony Corp. descended upon her. In 1984 they filed suit demanding $2.9 million in damages. What had she done? She had infringed their trademark! She was engaged in unfair competition! Consumers would be confused!

Florendo retained counsel, but to no avail. She offered to change the restaurant's name to "Sony Florendo's," but the Japanese tycoons were not amused. Big Sony wrung an agreement from Little Sony. They would drop the suit if she would abandon any use of her name. Three weeks ago a grace period expired, and now the name of "Sony" must disappear from the restaurant altogether.

Maryland's Sen. Barbara Mikulski wrote a hot letter to Akio Morita, the head of Sony Corp.: "Shame on you, Sony! I've known Sony Florendo for years. I can't understand how this woman is a threat to Sony Corp. She sells food, not electronics or anything that competes with your company. Sony Corp. may have the law on its side. But you do not have common sense or even common decency on your side. Why are you bullying her?"

A Sony vice chairman, N. Vander Dussen, responded with a syrupy letter saying the corporation had no intent to bully; it was only protecting its trademark. They had given Florendo a four-year period to comply with a court order. And Big Sony wished her well. So much for this troublesome woman.

The second incident involves operators of coal mines. A couple of weeks ago Lynn Martin, secretary of labor, spelled out an ugly story before a House committee. At least 500 mining companies, she charged, have flagrantly violated a major law governing mine safety. One of them, the giant Peabody Coal Co., largest in the nation, has pleaded guilty and accepted a $500,000 fine for tampering with evidence.

One of the perils of underground mining lies in heavy concentrations of coal dust. To protect against the hazard, some miners are randomly equipped with an air sampling device. This is a filter that traps ambient dust. After eight hours of exposure, the test filter is sent to a federal laboratory in Pittsburgh where it is weighed.

Martin told the committee that the laboratory found clear evidence of tampering. It appeared that some mine operators had carefully vacuumed dust out of the devices or had otherwise fiddled with the evidence before sending the filters to Pittsburgh. The Labor Department has imposed fines of $5 million for 5,000 violations at 847 mines.

The coal miner's life is a hard life. The risk of physical injury is compounded by the risk of contracting black lung disease. Affected workers file roughly 150,000 claims for compensation every year. It is unconscionable - no other word will do - for companies willfully to tamper with evidence that might lead to a lessening of the fatal dust.

Why does big business get to be bad business? In some instances, we have to surmise, the answer is greed, pure greed. Peabody's executives and underlings, we may speculate, wanted the filter evidence to show them to be in compliance with safety laws. If they were found not in compliance, they would risk heavy fines.

In the matter of Sony, the answer is stupidity, pure stupidity. Yes, it is important to protect a trademark, but Sony's lawyers must rank among the dumbest lawyers ever to file a lawsuit. As Mikulski said, the small restaurant in Baltimore was no threat whatever to the international electronics colossus. Corporate managers are supposed to have good judgment. Here the judgment was terrible.

I am curious about the knuckleheads at Peabody and Sony. Has anyone been fired? Reprimanded? Scolded? Maybe yes, more probably no. To read the business news these days is to reflect that all too often responsible parties tend to blunder on until they drag down their bonuses and retire.