No, not really. Even if it was it wouldn't excuse the action. He is 100 percent responsible for a truly despicable act. I think it is unforgivable in my opinion.
Let me put this another way. Jaime Lannister has one (well, maybe two if you count killing Ned's men in king's landing) "despicable" act. A failed murder attempt against Bran Stark, with the justification that his life and the lives of his sister and children were potentially forfeit if Bran reported what he saw.
Let's compare this to:
Sansa- whose lies were directly responsible for myca and lady being executed, because she was caught up in a princess fantasy
Cat Stark- who hung and killed (?) Pod Payne because Fuck Lannisters That's Why
Jeor Mormont- who allowed craster to use his own daughters as brood mares, and feed(?) male infants to the Others, because it was convenient for the Night's Watch
Arya Stark- who kills a teen servant escaping king's landing, has Jaquen kill two more servants at Harrenhall just because, leaves the Hound to die a slow death despite the fact that he saved her from a grisly death at the Red Wedding, and kills at least one other individual as part of a trial for the Faceless men
Danerys Targaryen- who let her dragons run wild, burn children alive, and eat them out of negligence
Theon Greyjoy- who kills two random common boys to cover up the fact that he can't find Bran and Rickon
Loras Tyrell- who kills three of his own men, distraught that Renly is dead
Stannis- who assassinated his own brother via melisandre's magic (i.e. the throne was "his" despite no one wanting him as king) and was "likely" to kill his nephew Edric Storm for power to gain the throne
Robert Baratheon- who approved of Tywin lannister's murder of Rhaegar's wife and children, and sent assassination attempts after Danerys when he found out she was pregnant
And those are just the people with Redeeming qualities. There's not even a need to bring up complete shitstains like Illyn Payne, Gregor Clegane, Roose Bolton, Ramsay Snow, Janos Slynt, Aerys Targaryen, and yes, Littlefinger for reasons I've already gone into.
There are no people with clean hands (ned aside), just various shades of Grey within the story. As these things go, 95% of the cast is worse than Jamie Lannister, who at least when he does shitty things, does them for others and not out of self interest. Littlefinger is one of those people that does a TON of shitty things entirely out of self interest, so saying "well, people like Jamie and he tried to kill Bran and that's the same" entirely miss the point, ignoring context, motivation, and behavioral patterns between the characters.