Sure it can be.
The law contained rules and regulations for washings, offerings, ceremonies, hygiene, food preparation, a criminal code, etc. One could follow the letter of the Law and not ever err in keeping the written down instructions and still not be saved because the Law was not established to be a vehicle for salvation. That's why Jesus said that one's righteousness had to exceed that of the Scribes and Pharisees.
They kept the letter of the Law, thinking that in it they had eternal life. They didn't keep the spirit of the Law, which is what the Law was really about.
In which case, they didn't keep it "blamelessly," which is what you claimed. "Thou shalt love the Lord thy God with thy whole heart and with thy whole soul and with thy whole mind and with thy whole strength" is part of the Law too.
Sure it can be.
Luke 11:42-53
“Woe to you Pharisees, because you give God a tenth of your mint, rue and all other kinds of garden herbs, but you neglect justice and the love of God. You should have practiced the latter without leaving the former undone.
“Woe to you Pharisees, because you love the most important seats in the synagogues and respectful greetings in the marketplaces.
“Woe to you, because you are like unmarked graves, which people walk over without knowing it.”
One of the experts in the law answered him, “Teacher, when you say these things, you insult us also.”
Jesus replied, “And you experts in the law, woe to you, because you load people down with burdens they can hardly carry, and you yourselves will not lift one finger to help them.
“Woe to you, because you build tombs for the prophets, and it was your ancestors who killed them. So you testify that you approve of what your ancestors did; they killed the prophets, and you build their tombs. Because of this, God in his wisdom said, ‘I will send them prophets and apostles, some of whom they will kill and others they will persecute.’ Therefore this generation will be held responsible for the blood of all the prophets that has been shed since the beginning of the world, from the blood of Abel to the blood of Zechariah, who was killed between the altar and the sanctuary. Yes, I tell you, this generation will be held responsible for it all.
“Woe to you experts in the law, because you have taken away the key to knowledge. You yourselves have not entered, and you have hindered those who were entering.”
When Jesus went outside, the Pharisees and the teachers of the law began to oppose him fiercely and to besiege him with questions, waiting to catch him in something he might say.