I thank you bros here for your patience to read such a long post, and I welcome any enlightenment.
I will say a few things which I am sure is not to your liking and what you wish to hear. Your story does not sound right and doesn't quite add up. You got up, went into the toilet for "less than a minute" (to shave and not to brush your teeth after a long sleep), and left the door "almost closed" on the claim it was because the maid was behind the door. Others may well see it as an attempt to hide what you, in the absence of your wife and family, intended to do to the maid from the camera trained on your toilet.
Whilst the results of the polygraph test is inadmissible in court, it plays a large part in the police's decision as to whether you should be charged. That they have done so indicate you have failed your polygraph test, i.e. you lied to at least some of the critical questions asked of you. It is highly unlikely that the police will press charges against you if they feel they do not have sufficient evidence to secure a conviction.
Section 71 was repealed six years ago in 2011, so you couldn't possibly have been charged under S71. Conviction can be attained under S354 based on "intent" and need not have to be actual physical contact. The "accidental" splash may well qualify as the "criminal force" you carried out, with the "intention" to commit OM against your maid. See similar examples from the PC of what may constitute "criminal force":
Extract from Section 350
(e) A throws a stone, intending or knowing it to be likely that the stone will be thus brought into contact with Z, or with Z’s clothes, or with something carried by Z, or that it will strike water and dash up the water against Z’s clothes, or something carried by Z. Here if the throwing of the stone produces the effect of causing any substance to come into contact with Z, or Z’s clothes, A has used force to Z; and if he has done so without Z’s consent, intending thereby to injure, frighten or annoy Z, he has used criminal force to Z.
(g) Z is bathing. A pours into the bath water which he knows to be boiling. Here A intentionally by his own bodily power causes such motion in the boiling water as brings that water into contact with Z, or with other water so situated that such contact must affect Z’s sense of feeling; A has therefore intentionally used force to Z; and if he has done this without Z’s consent, intending or knowing it to be likely that he may thereby cause injury, fear or annoyance to Z, A has used criminal force to Z.
As I said, your whole story doesn't quite add up and IMHO, not credible. I am sure you have left out critical details or have not told the whole truth. I suspect there was actual intent to molest, if not physical contact. The questionable decisions you made and actions you took (probably out of panic), as well as your maid's shriek and post-toilet conduct and actions, could not just be due to the innocuous and "accidental" splashed water. Your wife believing your innocence and the maid not being "chio" are irrelevant.
Sorry, I am sure this is not what you want to hear. But I thought it may be helpful for you to see it from the other side of the coin. If not for anything else, it may help you with your defense strategy. If this is not a troll and you are truly innocent as you say you are, a good lawyer should be able to win the case fairly easily. So try not to stinge or save by getting a cheap but screwed up lawyer with a lousy track record. Good luck and all the best.