director buys a falling stock?

I noticed on change in Directors interest that one of DFT's directors bought $17k of shares on market 2 weeks ago when the shares were 2 cents. In effect he converted some options into shares, but he could have just sold the oppies which he got $17k for/

The shares are now 1.7 cents or 15%. Can anyone think of a reason why he would have bought?

I was stopped out of DFT but still follow. They seem cheap given the number of customers they have if there was any sort of industry consolidation.