If my husband really wanted his divorce, then why didn't he MAKE SURE he was going to get one??

trying to understand the OW and my estranged husband

he filed and thought I wouldn't know. But I found out and was confused why he put the info on his complaint...totally different date of marriage but exact and correct dates for the births of our children. the date he put for our marriage was stating that we had our first born before we got married (actually had our first born 8 months after we got married)
Then the grounds he used was separation-in the state he lives in, separation is grounds but you can't file until after 18 months has passed. At the time he gave an incorrect date of separation, and stated we have been separated for 9 months, but when you do the math his date of separation he filed for and the date he filed on added to 11 mos. Prior to him filing though, the OW tried to call me several times and sent me a message on myspace and my e-mail which I did not repsond to.
At the time I didn't know what grounds he used...I really thought it would've been general indignities (same as irreconcilable differences, but you have to prove it). And I was going to counter file. But after I found out it was separation and know it hasn't even been 18 mos, I filed a motion to dismiss. I figured if he wanted to have this done for sure, that he would've MADE SURE he got everything correct the first time. On his complaint he did not ask for anything and said we don't have anything to split up (not true), did not state anything about custody and said he will pay child support "later".
So even though I found out 20 minutes after he filed (gut feeling and knew something was happeneing b/c he changed his number and so did OW), and after I found out what grounds he used, I did a lot of thinking and filed my response after 20 days (filed motion to dismiss). He was given 20 days to file a response back, then another 30 to amend his complaint and use a valid grounds for divorce in the state he filed in. He didn't do both. I believe he was seeing OW 1-2 mons before our separation.

OW is 20 yrs. old...6 years younger than me.

Now the case is dismissed and we are still legally married.

Could there be another reason why he filed?
Why didn't he amend his complaint?
If he really wanted to get this done, then why didn't he just lie on how long we've been separated or use general indignities as grounds?
If he really wanted this done, then why didn't he get it right the first time?

He also claimed he didn't have a job that's why he was able to get his filing fee waived.
So he attempted to represent himself.

Why won't OW leave him..aren't my children not enough to make her want to think about what she is doing? (they're 3 yrs. and one is 10 mos.)

He filed almost 4 mos ago. We have been separated for almost a year.
I filed for child support last August and it has just arrived in the state he lives in. He has other child support cases so this wouldn't be his first and second.

So right now I am waiting until Dec. 08 arrives that's the time he will be able to file based on separation or to see whether he will do it again under an invalid ground.

What can my husband really be up to?

Your insight IS GREATLY appreciated. Thanks in advance.


*******IT WOULD BE NICE TO GET A MAN'S PERSPECTIVE ON THIS***********