What part of 'they' inferred that there wasn't two witnesses?
They say unto him, Master, this woman was taken in adultery, in the very act John 8:4
Moreover that they must be two accusers before a person could be charged with a sin.
Then both the men, between whom the controversy is, shall stand before the LORD, before the priests and the judges, which shall be in those days; 18 And the judges shall make diligent inquisition: and, behold, if the witness be a false witness, and hath testified falsely against his brother; Then shall ye do unto him, as he had thought to have done unto his brother: so shalt thou put the evil away from among you. Deut 19:17-19
If two witnesses were required to charge a person with sin then nobody could make the judgment that a person had sinned without two witnesses that the person had sinned. Yet if a woman is raped then the rapist could not be be convicted of rape unless two witnesses testify that the woman was raped? Absolutely ridiculous, yet two witnesses were only required to put a person to death for any sin.
"...but one witness shall not testify against any person to cause him to die. Num 35:30
But of course they could also call up the stone to testify against a person, I know one member that thinks a stone can talk, but it can't be cross-examined since it written, "And Joshua said unto all the people, Behold, this stone shall be a witness unto us; for it hath heard all the words of the LORD which he spake unto us: it shall be therefore a witness unto you, lest ye deny your God." Josh 24:27
And again he stooped down, and wrote on the ground. And they which heard it, being convicted by their own conscience, went out one by one, beginning at the eldest, even unto the last:
John 8:8-9
So howbeit that Jesus found the woman guilty of adultery as evident by the fact he told the woman to go and sin no more?