The questions are interesting, and I have been following the debates back and forth. Those on both side argue theology and back themselves up with the Catechism. There is so much hand wringing over this question, and yet no one has looked for answers in the Bible. The unasked question is not "Can God bless a deception?" but "Has God blessed such deception before?"
In the book of Judges (Chapter 4), the Israelites are at war with the Canaanites. In the midst of a great battle the Canaanite general, Sisera, looks for safety in the tent of Jael, and Israelite woman.
" 'Come in, my lord, come in with me; do not be afraid.' So he went into her tent and she covered him with a rug." Judges 4:18 Jael made him to feel safe and protected. She promised to stand watch for his enemies. She made sure that he was comfortable....right up until she drove a tent spike into his head.
"Thus on that day God humbled the Canaanite king, Jabin, before the Israelites" Judges 4:23
Later, in the book of Judith, God again uses the guile of women to defeat his enemies.
When the forces of the Assyrian army laid siege to Judea, it was the widow Judith who God sent to defeat his enemies. She took off her mourning clothes, and dressed herself as a courtesan. She set out to win victory for her people, not with the sword, but with deception.
She prayed to God, "By guile of my lips strike down slave with master, and master with retainer. Break their pride by a woman's hand." Judith 9:10 and "Give me a beguiling tongue to wound and kill those who have formed such cruel designs against your covenant..." Judith 9:13
And God did. He delivered Holofernes, the Assyrian general, into her hands. She killed him with his own sword and returned to her people.
I understand the concern of many about the deceit used in the videos made by Lila Rose in her efforts to bring down Planned Parenthood. I'm made uneasy by it myself...and yet..... In the past, God has used the guile of women to bring down seemingly unconquerable enemies. He has blessed their actions and saved his people.
I do not believe that this is a case of the ends justifying the means. I believe that it is a woman doing the task which God has placed before her, using the gifts she has been given to complete that task.
Lila is our modern day Judith. She has disguised herself as their ally. She has found herself welcome in their midst. She has seen the evil of the opponent up close. She has placed herself in the care of the Almighty as she walks amongst His enemies. She has made sure that they feel safe with her and then like Judith, she is slaying them with their own sword.